1 Install grml to harddisk:
5 Notice: You can pre-select the partition for the partition selector
6 and mbr dialogs inside grml2hd using:
7 # grml2hd /dev/hda1 -mbr /dev/hda
9 See: man grml2hd + http://grml.org/grml2hd/
11 Install grml on software RAID level 1:
13 Create /dev/md0 (and some more /dev/md* devices) first of all:
14 # cd /dev && MAKEDEV dev
17 # mdadm --create --verbose /dev/md0 --level=raid1 \
18 --raid-devices=2 /dev/hda1 /dev/hdc1
20 Finally install grml on it:
21 # SWRAID='mbr-only' grml2hd /dev/md0 -mbr /dev/md0
23 See: man grml2hd + http://grml.org/grml2hd/
25 Install grml in non interactive mode with grml2hd:
27 Adjust configuration as needed:
28 # vim /etc/grml2hd/config
32 # GRML2HD_NONINTERACTIVE=yes grml2hd
38 Use with care and only if you really know what you are doing!
40 See: man grml2hd + http://grml.org/grml2hd/
46 Boot grml via network:
50 See: man grml-terminalserver + http://grml.org/terminalserver/
52 Deactivate error correction of zsh:
56 Run zsh-help for more information regarding zsh.
58 Disable automatic setting of title in GNU screen:
62 Set it manually e.g. via:
64 % screen -X title foobar
66 Run zsh-help for more information regarding zsh.
68 Do not use menu completion in zsh:
72 Run zsh-help for more information regarding zsh.
74 Run GNU screen with grml-configuration:
80 % screen -c /etc/grml/screenrc
82 Print out grml-version:
90 Configure mutt-ng / muttng:
94 Set up Inode-PPTP connection:
98 # grml-pptp-xdsl-students
100 Set up VPN / WLAN connection at TUG (TU Graz):
102 Set ESSID and request for ip-address via DHCP:
103 # iwconfig $DEVICE essid tug
106 Now run the main script:
109 After running the script an init script is available:
111 # /etc/init.d/vpnctug [start|stop]
113 Set up PPTP connection at VCG (Virtual Campus Graz):
123 # grml-vpn -k 2005 add 1000 192.168.20.1 192.168.20.2
127 Use encrypted files / partitions:
129 # grml-crypt <options>
135 # grml-crypt format /mnt/external1/encrypted_file /mnt/test
136 # cp big_file /mnt/test
137 # grml-crypt stop /mnt/test
141 # grml-crypt start /mnt/external1/encrypted_file /mnt/test
142 # grml-crypt stop /mnt/test
146 Change resolution of X:
148 % xrandr -s '1024x768'
150 Change resolution of framebuffer:
154 Configure newsreader slrn:
158 Configure grml system:
162 Or directly run scripts:
167 Lock screen (X / console):
171 Press ctrl-alt-x to lock a GNU screen session.
173 Change wallpaper in X:
175 % grml-wallpaper <press-tab>
177 Start X window system (XFree86 / Xorg / X.org):
179 % grml-x $WINDOWMANAGER
184 % grml-x -mode '1024x768' wmii
185 % grml-x -nosync wm-ng
187 Collect hardware information:
191 or run as root to collect some more information:
195 will generate a file named info.tar.bz2.
197 Configure hardware detection features of harddisk installation:
201 or manually edit /etc/grml/autoconfig[.small]
203 See: man grml-autoconfig
205 Bootoptions / cheatcodes / bootparams for booting grml:
207 On the grml-ISO if not running grml:
208 % less /cdrom/GRML/grml-cheatcodes.txt
211 % most /usr/share/doc/grml-docs/grml-cheatcodes.txt.gz
213 Report bugs to Debian's Bug Tracking System (BTS):
215 % reportbug --bts debian
217 or adjust /etc/reportbug.conf to your needs.
221 http://grml.org/bugs/
222 http://www.debian.org/Bugs/
224 Offline documentation:
228 Online documentation:
231 http://grml.org/docs/
232 http://wiki.grml.org/doku.php
234 Mount ntfs partition (read-write):
237 # ntfsmount /dev/hda1 /mnt/hda1
239 Overwrite specific file on an NTFS partition:
241 ntfscp /dev/hda1 /tmp/file_source path/to/file_target
243 Resize an NTFS partition:
249 ntfsresize -n -s 10G /dev/hda1 # testcase
250 ntfsresize -s 10G /dev/hda1 # testing was successfull, now really resize partition
251 cfdisk /dev/hda # delete partition hda1, create new one with 10000MB and fs-type 07 (NTFS)
253 Modify resolution for intel graphic chipsets:
259 # 915resolution 4d 1400 1050
261 Connect bluetooth mouse:
265 ... and press 'connect' button on your bluetooth device.
267 Connect bluetooth headset:
271 ... and press 'connect' button on your bluetooth device.
273 Secure delete file / directory / partition:
279 Also take a look at shred(1), sfill(1) and http://dban.sourceforge.net/
281 Use grml on Samsung X20 laptop:
283 # apt-get install grml-samsung-x20
285 See: http://www.michael-prokop.at/computer/samsung_x20.html
287 Development information regarding grml:
289 http://grml.supersized.org/
293 #grml on irc.freenode.org - http://grml.org/irc/
294 http://grml.org/contact/
296 Join the grml mailinglist:
298 http://grml.org/mailinglist/
302 http://grml.org/donations/
304 Commercial support / system administration / adjusted live-cds:
306 grml-solutions: http://grml.org/solutions/
308 Information regarding the kernel provided by grml:
310 http://grml.org/kernel/
312 SMTP command-line test tool:
318 % swaks -s $MAILSERVER -tlsc -a -au $ACCOUNT -ap $PASSWORD -f $MAILADRESSE -t $MAILADRESSE
322 NTFS related packages:
328 Modify service through init script:
335 # /etc/init.d/lvm start
339 # jstest /dev/input/js0
343 % mplayer /path/to/movie
345 Use webcam with mplayer:
347 % mplayer tv:// -tv driver=v4l:width=352:height=288:outfmt=yv12:device=/dev/video0
349 Powerful network discovery tool:
353 Grab an entire CD and compress it to Ogg/Vorbis,
354 MP3, FLAC, Ogg/Speex and/or MPP/MP+(Musepack) format:
358 Show a console session in several terminals:
362 Switch behaviour of caps lock key:
366 grep with Perl-compatible regular expressions:
370 ncp: a fast file copy tool for LANs
375 Remote (receive file):
378 utility for sorting records in complex ways:
382 a smaller, cheaper, faster SED implementation:
390 See: http://grml.org/zsh/
392 zsh reference card for grml system:
395 /usr/share/doc/grml-docs/zsh/grml-zsh-refcard.pdf.gz
399 % for i in foo* ; do mv "$i" "bar${i/foo}" ; done
401 % prename 's/foo/bar/' foo*
403 % zmv 'foo(*)' 'bar$1'
405 Test TFT / LCD display:
413 Improved grep version:
417 Grep with highlighting:
419 % grep --color=auto ...
422 Extract matches when grepping:
425 % ifconfig | grepc 'inet addr:(.*?)\s'
426 % ifconfig | glark --extract-matches 'inet addr:(.*?)\s'
428 Output text as sound:
431 % xsay # when running X and text selected via mouse
433 Adjust a grml harddisk (grml2hd) installation:
437 Get information on movie files:
439 % tcprobe -i file.avi
441 Get an overview of your image files:
443 % convert 'vid:*.jpg' thumbnails.jpg
445 List all standard defines:
447 % gcc -dM -E - < /dev/null
449 Send a mail as reminder:
451 echo "mail -s 'check TODO-list' $MAILADDRESS < /dev/null" | at 23:42
453 ncurses-based presentation tool:
457 See: man tpp and /usr/share/doc/tpp/examples/
459 Use ICQ / Jabber / Yahoo! / AIM / MSN /... on command line:
463 Use IRC on command line:
469 % vimdiff file1 file2
475 Moving between diffs:
485 Hardware monitoring without kernel dependencies:
489 Install grml-iso to usb-stick:
491 % grml2usb grml.iso /mount/point
493 Use mplayer on framebuffer console:
495 % mplayer -vo fbdev ...
497 Use links2 on framebuffer console:
499 % links2 -driver fb ...
501 Switch language / keyboard:
503 * use the bootparam lang to set language environment ($LANG, $LC_ALL, $LANGUAGE)
504 * use the bootparams keyboard / xkeyboard to activate specific keyboard layout
505 Usage example: 'grml lang=us keyboard=de xkeyboard=de'
507 Or run one of the following commands:
511 # loadkeys i386/qwertz/de-latin1-nodeadkeys.kmap.gz # console
514 Switch setting of caps-control key (switch between ctrl + shift) on keyboard:
518 Mount usb device / usb stick:
520 % mount /mnt/external1 # corresponds to /dev/sda1
522 % mount /mnt/external # corresponds to /dev/sda
524 Install Sun Java packages:
526 Download j2re.bin-file from http://java.sun.com/downloads/index.html and run
528 # apt-get install java-package
529 # fakeroot make-jpkg j2re-*.bin
530 # dpkg -i sun-j2re*.deb
531 # update-alternatives --config java
535 ddrescue is an improved version of dd which tries to read and
536 if it fails it will go on with the next sectors, where tools
543 How to make an audio file (e.g. Musepack format) out of a DVD track:
545 % mkfifo /tmp/fifo.wav
546 % mppenc /tmp/fifo.wav track06.mpc &
547 % mplayer -vo null -vc null -ao pcm:fast:file=/tmp/fifo.wav -dvd-device /dev/dvd dvd://1 -chapter 6-6
549 Adjust the mppenc line with the encoder you would like to use,
550 for example 'oggenc -o track06.ogg /tmp/fifo.wav' for ogg files.
554 % mplayer -vo null -dumpaudio -dumpfile track06.raw -aid N -dvd-device /dev/dvd dvd://1 -chapter 6-6
555 to extract audio without processing, where 'N' is the corresponding audio channel (see 'man mplayer')
557 Usage example for getting a PCM/wave file from audio channel 128:
558 % mplayer -vo null -vc null -ao pcm:fast:file=track06.wav -aid 128 -dvd-device /dev/dvd dvd://6
560 Create simple chroot:
562 # make_chroot_jail $USERNAME
564 Convert DOS formated file to unix format:
566 sed 's/.$//' dosfile > unixfile # assumes that all lines end with CR/LF
567 sed 's/^M$//' dosfile > unixfile # in bash/tcsh, press Ctrl-V then Ctrl-M
568 sed 's/\x0D$//' dosfile > unixfile # gsed 3.02.80, but top script is easier
569 awk '{sub(/\r$/,"");print}' # assumes EACH line ends with Ctrl-M
570 gawk -v BINMODE="w" '1' infile >outfile # in DOS environment; cannot be done with
571 # DOS versions of awk, other than gawk
572 tr -d \r < dosfile > unixfile # GNU tr version 1.22 or higher
573 tr -d '\015' < dosfile > unixfile # use octal value for "\r" (see man ascii)
574 tr -d '[\015\032]' < dosfile > unixfile # sometimes ^Z is appended to DOS-files
575 vim -c ":set ff=unix" -c ":wq" file # convert using vim
576 vim -c "se ff=dos|x" file # ... and even shorter ;)
577 recode ibmpc..lat1 file # convert using recode
578 echo -e "s/\r//g" > dos2unix.sed; sed -f dos2unix.sed < dosfile > unixfile
580 Save live audio stream to file:
582 % mplayer -ao pcm:file=$FILE
586 % mencoder mms://file.wmv -o $FILE -ovc copy -oac copy
590 % mimms mms://file.wmv
596 % avimerge -i *.avi -o blub.avi
600 % cat *.mpg > blub.mpg
604 % mencoder file1.wmv -ovc lavc -oac lavc -ofps 25 -srate 48000 -mc 0 -noskip -forceidx -o file1.avi
605 % mencoder file2.wmv -ovc lavc -oac lavc -ofps 25 -srate 48000 -mc 0 -noskip -forceidx -o file2.avi
606 % avimerge -i file1.avi file2.avi -o blub.avi
608 Display MS-Word file:
610 % strings file.doc | fmt | less
616 Convert MS-Word file to postscript:
618 % antiword -p a4 file.doc > file.ps
620 Convert manual to postscript:
622 % zcat /usr/share/man/man1/zsh.1.gz | groff -man > zsh.1.ps
624 % man -t zsh > zsh.ps
628 % dd if=/dev/mem bs=1k skip=768 count=256 2>/dev/null | strings -n 8
630 Read HTTP via netcat:
632 echo "GET / HTTP/1.0\r\n\r\n" | netcat $DOMAIN 80
634 Get X ressources for specific program:
636 % xrdb -q |grep -i xterm
638 Get windowid of specific X-window:
640 % xwininfo -int | grep "Window id:" | cut -d ' ' -f 4
642 Get titel of specific X-window:
646 check locale - LC_MESSAGES:
648 % locale -ck LC_MESSAGES
650 Create random password:
654 % dd if=/dev/urandom bs=14 count=1 | hexdump | cut -c 9-
656 Get tarballs of various Linux Kernel trees:
659 to get the current stable 2.6 release
662 to get a list of all supported trees
664 Transfer your SSH public key to another host:
666 % ssh-copy-id -i ~/.ssh/id_dsa.pub user@remote-system
668 % cat $HOME/.ssh/id_rsa.pub | ssh user@remote-system 'cat >> .ssh/authorized_keys'
670 Update /etc/fstab entries:
674 See "man grml-rebuildfstab" for more details about
675 generation of /etc/fstab (including stuff like
676 fs LABELs / UUIDs,...).
678 Fetch and potentially change SCSI device parameters:
684 reclaim disk space by linking identical files together:
688 Find and remove duplicate files:
692 Perform layer 2 attacks:
698 Guess PC-type hard disk partitions / partition table:
702 Perform a standard scan:
705 Write back the guessed table:
706 # gpart -W /dev/ice /dev/ice
708 Develop, test and use exploit code with the Metasploit Framework:
711 wget http://framework-mirrors.metasploit.com/msf/downloader/framework-3.0.tar.gz
712 unp framework-3.0.tar.gz
716 Useful documentation:
718 % w3m /usr/share/doc/Debian/reference/reference.en.html
720 % xpdf =(zcat /usr/share/doc/Debian/reference/reference.en.pdf.gz)
722 http://grml.org/docs/ grml Documentation
723 http://wiki.grml.org/ grml Wiki
724 http://www.debian.org/doc/ Debian Documentation
725 http://wiki.debian.org/ Debian Wiki
726 http://www.gentoo.org/doc/en/ Gentoo Documentation
727 http://gentoo-wiki.com/ Gentoo Wiki
728 http://www.tldp.org/ The Linux Documentation Project
732 % fortune debian-hints
736 % fortune debian-hints
737 % dpkg -L funny-manpages
739 Backup master boot record (MBR):
741 # dd if=/dev/ice of=/tmp/backup_of_mbr bs=512 count=1
743 Backup partition table:
745 # sfdisk -d /dev/hda > hda.out
747 Restore partition table:
749 # sfdisk /dev/hda < hda.out
751 Clone disk via network using netcat:
754 # nc -vlp 30000 > hda1.img
756 # dd if=/dev/hda1 | nc -vq 0 192.168.1.2 30000
758 Adjust blocksize (dd's option bs=...) and include 'gzip -c'
761 # dd if=/dev/hda1 bs=32M | gzip -c | nc -vq 0 192.168.1.2 30000
763 Backup specific directories via cpio and ssh:
765 # for f in directory_list; do find $f >> backup.list done
766 # cpio -v -o --format=newc < backup.list | ssh user@host "cat > backup_device"
770 This one uses CPU cycles on the remote server to compare the files:
771 # ssh target_address cat remotefile | diff - localfile
772 # cat localfile | ssh target_address diff - remotefile
774 This one uses CPU cycles on the local server to compare the files:
775 # ssh target_address cat <localfile "|" diff - remotefile
777 Useful tools for cloning / backups:
779 * dd: convert and copy a file
780 * dd_rescue: copies data from one file (or block device) to another
781 * pcopy: a replacement for dd
782 * partimage: back up and restore disk partitions
783 * dirvish: Disk based virtual image network backup system
784 * devclone: in-place filesystem conversion -- device cloning
785 * ntfsclone: efficiently clone, image, restore or rescue an NTFS
786 * dump: ext2/3 filesystem backup
787 * udpcast: multicast file transfer tool
788 * cpio: copy files to and from archives
789 * pax: read and write file archives and copy directory hierarchies
790 * netcat / ssh / tar / gzip / bzip2: additional helper tools
792 Use grml as a rescue system:
796 * dd: convert and copy a file
797 * ddrescue: copies data from one file or block device to another
798 * partimage: Linux/UNIX utility to save partitions in a compressed image file
799 * cfdisk: Partition a hard drive
800 * nparted: Newt and GNU Parted based disk partition table manipulator
801 * parted-bf: The GNU Parted disk partition resizing program, small version
802 * testdisk: Partition scanner and disk recovery tool
803 * gpart: Guess PC disk partition table, find lost partitions
807 * e2fsprogs: ext2 file system utilities and libraries
808 * e2tools: utilities for manipulating files in an ext2/ext3 filesystem
809 * e2undel: Undelete utility for the ext2 file system
810 * ext2resize: an ext2 filesystem resizer
811 * recover: Undelete files on ext2 partitions
815 * reiser4progs: administration utilities for the Reiser4 filesystem
816 * reiserfsprogs: User-level tools for ReiserFS filesystems
820 * xfsdump: Administrative utilities for the XFS filesystem
821 * xfsprogs: Utilities for managing the XFS filesystem
825 * jfsutils: utilities for managing the JFS filesystem
829 * ntfsprogs: tools for doing neat things in NTFS partitions from Linux
830 * salvage-ntfs: free NTFS data recovery tools
831 * scrounge-ntfs: data recovery program for NTFS file systems
832 * ntfsresize: resize ntfs partitions
834 Get ASCII value of a character with zsh:
836 % char=N ; print $((#char))
838 Convert a collection of mp3 files to wave or cdr using zsh:
840 % for i (./*.mp3){mpg321 --w - $i > ${i:r}.wav}
842 Convert images (foo.gif to foo.png) using zsh:
844 % for i in **/*.gif; convert $i $i:r.png
846 Remove all "non txt" files using zsh:
850 Remote Shell Using SSH:
853 % ssh -NR 3333:localhost:22 user@yourhost
856 % ssh user@localhost -p 3333
858 Reverse Shell with Netcat:
861 % netcat -v -l -p 3333 -e /bin/sh
864 % netcat 192.168.0.1 3333
866 Reverse Shell via SSH:
868 local host (inside the network):
869 % ssh -NR 1234:localhost:22 remote_host
871 remote host (outside the network):
872 % ssh localhost -p 1234
874 Remove empty directories with zsh:
876 % rmdir ./**/*(/od) 2> /dev/null
878 Find all the empty directories in a tree with zsh:
882 Find all files without a valid owner and change ownership with zsh:
884 % chmod user /**/*(D^u:${(j.:u:.)${(f)"$(</etc/passwd)"}%%:*}:)
886 Display the 5-10 last modified files with zsh:
888 % print -rl -- /path/to/dir/**/*(D.om[5,10])
890 Find and list the ten newest files in directories and subdirs (recursive) with zsh:
892 % print -rl -- **/*(Dom[1,10])
894 Find most recent file in a directory with zsh:
896 % setopt dotglob ; print directory/**/*(om[1])
898 Tunnel all traffic through an external server:
900 % ssh -ND 3333 username@external.machine
902 Then set the SOCKS4/5 proxy to localhost:3333.
903 Check whether it's working by surfing e.g. to checkip.dyndns.org
905 Tunnel everything through SSH via tsocks:
907 set up the SSH proxy on the client side:
909 % ssh -ND 3333 user@remote.host.example.com
911 Adjust /etc/tsocks.conf afterwards (delete all other lines):
916 For programs who natively support proxying connections (e.g. Mozilla
917 Firefox) you can now set the proxy address to localhost port 3333.
919 All other programs which's connections you want to tunnel through your
920 external host are prefixed with tsocks, e.g.:
922 % tsocks netcat example.com 80
923 % tsocks irssi -c irc.quakenet.eu.org -p 6667
925 If you call tsocks without parameters it executes a shell witht the
926 LD_PRELOAD environment variable already set and exported.
928 smartctl - control and monitor utility for harddisks using Self-Monitoring,
929 Analysis and Reporting Technology (SMART):
931 # smartctl --all /dev/ice
933 If you want to use smartctl on S-ATA (sata) disks use:
935 # smartctl -d ata --all /dev/sda
938 # smartctl -t offline /dev/ice
941 # smartctl -t short /dev/ice
943 Display results of test:
944 # smartctl -l selftest /dev/ice
946 Query device information:
947 # smartctl -i /dev/ice
949 Mount a BSD / Solaris partition:
951 # mount -t ufs -o ufstype=ufs2 /dev/hda1 /mnt/hda1
953 Use ufstype 44bsd for FreeBSD, NetBSD, OpenBSD (read-write).
954 Use ufstype ufs2 for >= FreeBSD 5.x (read-only).
955 Use ufstype sun for SunOS (Solaris) (read-write).
956 Use ufstype sunx86 for SunOS for Intel (Solarisx86) (read-write).
958 See /usr/share/doc/linux-doc-$(uname -r)/Documentation/filesystems/ufs.txt.gz
961 Read BIOS (and or BIOS) password:
963 # dd if=/dev/mem bs=512 skip=2 count=1 | hexdump -C | head
965 Clone one of the kernel trees via git:
967 git clone rsync://rsync.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
969 This path defines the tree. See http://kernel.org/git/ for an overview.
971 Mount filesystems over ssh protocol:
973 % sshfs user@host:/remote_dir /mnt/test
977 % fusermount -u /mnt/test
979 (Notice: requires fuse kernel module)
981 Install Gentoo using grml:
983 See http://www.gentoo.org/doc/en/altinstall.xml
985 Install (plain) Debian (sarge release) via grml:
987 Assuming you want to install Debian to sda1:
989 mkfs.ext3 /dev/sda1 # make an ext3 filesystem on /dev/sda1
990 mount -o rw,suid,dev /dev/sda1 /mnt/test # now mount the new partition
991 debootstrap sarge /mnt/test ftp://ftp.tugraz.at/mirror/debian # get main packages from a debian-mirror
992 chroot /mnt/test /bin/bash # let's chroot into the new system
993 mount -t devpts none /dev/pts # ...otherwise running base-config might fail ("Terminated" or "openpty failed")
994 mount -t proc none /proc # make sure we also have a mounted /proc
995 base-config # now configure some main settings
996 vi /etc/mkinitrd/mkinitrd.conf # adjust $ROOT (to /dev/sda1) for your new partition, autodetection will fail in chroot
997 cd /dev ; ./MAKEDEV generic # make sure we have all necessary devices for lilo
998 apt-get install lilo linux-image-2.6.12-1-386 # install lilo and a kernel which fits your needs
999 cp /usr/share/doc/lilo/examples/conf.sample /etc/lilo.conf # let's use a template
1000 vi /etc/lilo.conf && lilo # adjust the file for your needs and run lilo afterwards
1001 umount /proc ; umount /dev/pts # we do not need them any more
1002 exit # now leave chroot
1003 cp /etc/hosts /etc/fstab /mnt/test/etc/ # you might want to take the existing files...
1004 cp /etc/network/interfaces /mnt/test/etc/network/ # ...from the running grml system for your new system
1005 umount /mnt/test && reboot # unmount partition and reboot...
1007 See also: http://www.debian.org/releases/stable/i386/apcs04.html.en
1008 Avoid all of the above steps - use grml-debootstrap(8) instead!
1010 Install (plain) Debian (etch release) via grml
1012 Assuming you want to install Debian to sda1:
1014 mkfs.ext3 /dev/sda1 # make an ext3 filesystem on /dev/sda1
1015 mount -o rw,suid,dev /dev/sda1 /mnt/test # now mount the new partition
1016 debootstrap etch /mnt/test ftp://ftp.tugraz.at/mirror/debian # get main packages from a debian-mirror
1017 chroot /mnt/test /bin/bash # let's chroot into the new system
1018 mount -t proc none /proc # make sure we have a mounted /proc
1019 apt-get install locales console-data # install locales
1020 dpkg-reconfigure locales console-data # adjust locales to your needs
1021 apt-get install vim most zsh screen less initrd-tools file grub \
1022 usbutils pciutils bzip2 sysfsutils dhcp3-client resolvconf \
1023 strace lsof w3m # install useful software
1024 apt-get install linux-headers-2.6-686 linux-image-686 # install current kernel
1026 echo "127.0.0.1 localhost" > /etc/hosts # adjust /etc/hosts and network:
1027 cat >> /etc/network/interfaces << EOF
1028 iface lo inet loopback
1029 iface eth0 inet dhcp
1034 ln -sf /usr/share/zoneinfo/Europe/Vienna /etc/localtime # adjust timezone and /etc/fstab:
1035 cat >> /etc/fstab << EOF
1036 sysfs /sys sysfs auto 0 0
1037 proc /proc proc defaults 0 0
1038 /dev/sda1 / ext3 defaults,errors=remount-ro 0 1
1039 /dev/sda2 none swap sw 0 0
1040 /dev/cdrom /mnt/cdrom0 iso9660 ro,user,noauto 0 0
1042 passwd # set password of user root
1044 mkdir /boot/grub # setup grub
1045 cp /usr/share/doc/grub/examples/menu.lst /boot/grub
1046 cat >> /boot/grub/menu.lst << EOF
1047 title Debian Etch, kernel 2.6.18-3-686 (on /dev/sda1)
1049 kernel /boot/vmlinuz-2.6.18-3-686 root=/dev/sda1 ro
1050 initrd /boot/initrd.img-2.6.18-3-686
1052 vim /boot/grub/menu.lst # adjust grub configuration to your needs
1053 cd /dev && MAKEDEV generic # create default devices
1054 cp -i /usr/lib/grub/i386-pc/* /boot/grub/ # copy stage-files to /boot/grub/
1055 grub install # now install grub, run in grub-cmdline following commands:
1059 umount -a # unmount all filesystems in chroot and finally:
1060 exit # exit the chroot and:
1063 If you want to use lilo instead of grub take a look at
1064 /usr/share/doc/lilo/examples/conf.sample or use the following template:
1066 cat > /etc/lilo.conf << EOF
1067 # This allows booting from any partition on disks with more than 1024 cylinders.
1070 # Specifies the boot device
1073 # Specifies the device that should be mounted as root.
1076 # use Debian on software raid:
1077 # raid-extra-boot=mbr-only
1085 image=/boot/vmlinuz-2.6.18-grml
1089 initrd=/boot/initrd.img-2.6.18-grml
1092 See also: http://www.debian.org/releases/stable/i386/apcs04.html.en
1093 Avoid all of the above steps - use grml-debootstrap(8) instead!
1095 Convert files from Unicode / UTF-8 to ISO:
1097 % iconv -c -f utf8 -t iso-8859-15 < utffile > isofile
1101 % iconv -f iso-8859-15 -t utf8 < isofile > utffile
1103 Assign static setup for network cards (eth0 and eth1) via udev:
1105 First method - manual:
1106 ~~~~~~~~~~~~~~~~~~~~~~
1107 Get information for SYSFS address:
1108 # udevinfo -a -p /sys/class/net/eth0/ | grep address
1110 Then create udev rules:
1111 # cat /etc/udev/network.rules
1113 KERNEL=="eth*", SYSFS{address}=="00:00:00:00:00:01", NAME="wlan0"
1114 KERNEL=="eth*", SYSFS{address}=="00:00:00:00:00:02", NAME="lan0"
1115 # do not match eth* drivers but also e.g. firewire stuff:
1116 ACTION=="add", SUBSYSTEM=="net", SYSFS{address}=="00:00:00:00:00:03", NAME="1394"
1118 Now activate the rules:
1119 # cd /etc/udev/rules.d/ && ln -s ../network.rules z35_network.rules
1121 Unload the drivers, restart udev and load the drivers again to activate
1124 Second method - automatic:
1125 ~~~~~~~~~~~~~~~~~~~~~~~~~~
1126 Run /lib/udev/write_net_rules shipped with recent udev versions:
1128 # INTERFACE=wlan1 /lib/udev/write_net_rules 00:00:00:00:00:04
1130 This command will create /etc/udev/rules.d/z25_persistent-net.rules containing:
1132 SUBSYSTEM=="net", DRIVER=="?*", SYSFS{address}=="00:00:00:00:00:04", NAME=wlan1
1134 See /usr/share/doc/udev/writing_udev_rules/index.html for more information.
1136 Change the suffix from *.sh to *.pl using zsh:
1139 % zmv -W '*.sh' '*.pl'
1141 Generate SSL certificate:
1143 Create self signed certificate (adjust /etc/ssl/openssl.cnf if necessary):
1144 # openssl req -x509 -newkey rsa:1024 -keyout keyfile -out certfile -days 9999 -nodes
1147 # openssl x509 -in certfile -text
1149 Verify against CA certificate:
1150 # openssl verify -CAfile cacert.crt -verbose -purpose sslserver
1152 Generate 2048bit RSA-key:
1153 # openssl req -new -x509 -keyout pub-sec-key.pem -out pub-sec-key.pem -days 365 -nodes
1155 As before but add request to existing key pub-sec-key.pem:
1156 # openssl req -new -out request.pem -keyin pub-sec-key.pem
1158 Show request request.pem:
1159 # openssl req -text -noout -in request.pem
1161 Verify signature of request request.pem:
1162 # openssl req -verify -noout -in request.pem
1164 Generate SHA1 fingerprint (modulo key) of request.pem:
1165 # openssl req -noout -modulus -in request.pem | openssl sha1 -c
1167 Generate 2048bit RSA-key and put it to pub-sec-key.pem. Save self signed certificate in self-signed-certificate.pem:
1168 # openssl req -x509 -days 365 -newkey rsa:2048 -out self-signed-certificate.pem -keyout pub-sec-key.pem
1170 As before but create self signed certificate based on existing key pub-sec-key.pem:
1171 # openssl req -x509 -days 365 -new -out self-signed-certificate.pem -key pub-sec-key.pem
1173 Generate new request out of existing self signed certificate:
1174 # openssl x509 -x509toreq -in self-signed-certificate.pem -signkey pub-sec-key.pem -out request.pem
1176 Display certificate self-signed-certificate.pem in plaintext:
1177 # openssl x509 -text -noout -md5 -in self-signed-certificate.pem
1179 Check self signed certificate:
1180 # openssl verify -issuer_checks -CAfile self-signed-certificate.pem self-signed-certificate.pem
1182 Estable OpenSSL-connection using self-signed-certificate.pem and display certificate:
1183 # openssl s_client -showcerts -CAfile self-signed-certificate.pem -connect www.example.com:443
1185 Generate ssl-certificate for use with apache2:
1187 export RANDFILE=/dev/random
1188 mkdir /etc/apache2/ssl/
1189 openssl req $@ -new -x509 -days 365 -nodes -out /etc/apache2/ssl/apache.pem -keyout /etc/apache2/ssl/apache.pem
1190 chmod 600 /etc/apache2/ssl/apache.pem
1192 Also take a look at make-ssl-cert (debconf wrapper for openssl):
1194 # /usr/sbin/make-ssl-cert /usr/share/ssl-cert/ssleay.cnf /etc/apache2/apache.pem
1196 and mod-ssl-makecert (utility to create SSL certificates in /etc/apache/ssl.*/).
1198 Change Windows NT password(s):
1200 # mount -o rw /mnt/hda1
1201 # cd /mnt/hda1/WINDOWS/system32/config/
1202 # chntpw SAM SECURITY system
1204 Notice: if mounting the partition read-write did not work (check syslog!)
1205 try using mount.ntfs-3g instead: mount.ntfs-3g /dev/hda1 /mnt/hda1
1207 (Be careful with deactivating syskey!)
1209 glark - replacement for grep written in Ruby:
1211 A replacement for (or supplement to) the grep family, glark offers:
1212 Perl compatible regular expressions, highlighting of matches,
1213 context around matches, complex expressions and automatic exclusion
1218 % glark -y keyword file # display only the region that matched, not the entire line
1219 % glark -o format print *.h # search for either "printf" or "format"
1221 More information: man glark
1223 Find CD burning device(s):
1225 General information on CD-ROM:
1226 % cat /proc/sys/dev/cdrom/info
1228 Scan using ATA Packet specific SCSI transport:
1229 # cdrecord -dev=ATA -scanbus
1230 # cdrecord-prodvd -s -scanbus dev=ATA
1232 Get specific information for /dev/ice:
1233 # cdrecord dev=/dev/ice -scanbus
1235 Create devices in /dev on udev:
1237 For example create md devices (/dev/md0, /dev/md1,...):
1238 # cd /dev ; WRITE_ON_UDEV=1 ./MAKEDEV md
1240 Identify network device (NIC):
1242 # ethtool -i $DEVICE
1244 Show NIC statistics:
1246 # ethtool -S $DEVICE
1248 If your NIC shows some aging signs, you may want to be sure:
1250 # ethtool -t $DEVICE
1252 Disable TCP/UDP checksums:
1254 # ethtool -K $DEVICE tx off
1256 grml2hd seems to hang? Getting Squashfs errors? Problems while booting?
1258 Switch to tty12 and take a look at the syslog. If you see something like:
1260 SQUASHFS error: zlib_fs returned unexpected result 0x........
1261 SQUASHFS error: Unable to read cache block [.....]
1262 SQUASHFS error: Unable to read inode [.....]
1264 your ISO/CD-ROM very probably is not ok. Verify it via booting with grml testcd.
1265 Check your CD low-level via running:
1267 # readcd -c2scan dev=/dev/cdrom
1269 If the medium really is ok and it still fails try to boot with deactivated DMA
1270 via using grml nodma at the bootprompt.
1272 Write a Microsoft compatible boot record (MBR) using ms-sys
1274 Write a Windows 2000/XP/2003 MBR to device:
1276 # ms-sys -m /dev/ice
1278 Use a Vodafone 3G Datacard (UMTS) with Linux:
1280 Plug in your vodafone card and check in syslog whether the appropriate
1281 (probably /dev/ttyUSB0 or /dev/noz0) has been created. If so run:
1284 # wvdial --config /etc/wvdial.conf.umts $PROFILE
1287 # gcom -d /dev/ttyUSB0
1288 # wvdial --config /etc/wvdial.conf.umts a1usb
1291 # wvdial --config /etc/wvdial.conf.umts tmnozomi
1294 # wvdial --config /etc/wvdial.conf.umts dreiusb
1296 If you receive invalid DNS nameservers when connecting, like:
1299 --> primary DNS address 10.11.12.13
1300 --> secondary DNS address 10.11.12.14
1302 just provide a working nameserver to resolvconf via:
1304 # echo "nameserver 80.120.17.70" | resolvconf -a ppp0
1306 Notice: some vodafone cards require the nozomi driver (run 'modprobe nozomi' on
1307 your grml system), some other ones require the sierra driver (run
1310 If your device isn't supported by usbserial yet, manually provide vendor and
1311 product ID when loading the usbserial module. Usage example:
1315 Bus 004 Device 008: ID 1199:6813 Sierra Wireless, Inc.
1317 # modprobe usbserial vendor=0x1199 product=0x6813
1319 hdparm - get/set hard disk parameters
1321 Display the identification info that was obtained from the drive at boot time,
1323 # hpdarm -i /dev/ice
1325 Request identification info directly from the drive:
1326 # hpdarm -I /dev/ice
1328 Perform timings of device + cache reads for benchmark and comparison purposes:
1329 # hdparm -tT /dev/ice
1331 bonnie++ - program to test hard drive performance.
1333 # mkdir /mnt/benchmark
1334 # mount /dev/ice /mnt/benchmark
1335 # chmod go+w /mnt/benchmark
1336 # bonnie -u grml -d /mnt/benchmark -s 2000M
1338 Use gizmo with a bluetooth headset:
1340 % DEVICE="/dev/dsp$(awk '/- BT Headset/ {print $1}' /proc/asound/cards)"
1341 % gizmo --mic $DEVICE --speaker $DEVICE
1343 Scan a v4l device for TV stations:
1345 % scantv -c /dev/video0 -C /dev/vbi0 -o ~/.xawtv
1347 Then running xawtv should work:
1351 Run apt-get with timeout of 3 seconds:
1353 # apt-get -o acquire::http::timeout=3 update
1355 Debian GNU/Linux device driver check page
1357 % $BROWSER http://kmuto.jp/debian/hcl/index.cgi
1359 Use dd with status line:
1361 # dd if=/dev/ice conv=noerror,notrunc,sync | buffer -S 100k | dd of=/tmp/file
1363 Generate a 512k file of random data with status bar:
1365 % dd if=/dev/random bs=1024 count=512 | bar -s 512k -of ./random
1367 Install Grub instead of lilo on grml installation (grml2hd):
1372 adjust grub's configuration file menu.lst:
1373 # $EDITOR /boot/grub/menu.lst
1375 now install grub (usage example for /dev/sda1):
1380 Install Ubuntu using grml:
1382 See https://wiki.ubuntu.com/Installation/FromKnoppix
1384 Resize ext2 / ext3 partition:
1386 # tune2fs -O '^has_journal' /dev/iceX # disable journaling
1387 # fsck.ext2 -v -y -f /dev/iceX # check the filesystem
1388 # resize2fs -p /dev/iceX $SIZE # resize it (adjust $SIZE)
1389 # fdisk /dev/ice # adjust partition in partition table
1390 # fsck.ext2 -v -y -f /dev/iceX # check filesystem again
1391 # resize2fs -p /dev/iceX # resize it to maximum
1392 # tune2fs -j /dev/iceX # re-enable journal
1394 Tune ext2 / ext3 filesystem:
1396 Check partition first:
1398 # tune2fs -l /dev/iceX
1400 If you don't see dir_index in the list, then enable it:
1402 # tune2fs -O dir_index /dev/iceX
1404 Now run e2fsck with the -D option to have the directories optimized:
1406 # e2fsck -D /dev/iceX
1408 Notice: since e2fsprogs (1.39-1) filesystems are created with
1409 directory indexing and on-line resizing enabled by default.
1411 Search for printers via network:
1413 # pconf_detect -m NETWORK -i 192.168.0.1/24
1415 Mount a remote directory via webdav (e.g. Mediacenter of GMX):
1417 # mount -t davfs https://mediacenter.gmx.net/ /mnt/test
1419 System-Profiling using oprofile:
1424 # opcontrol --setup --no-vmlinux --event=CPU_CLK_UNHALTED:500000:0:1:1 --separate=library
1429 Now $DO_SOME_TASKS...
1432 # opcontrol --shutdown
1434 Then take a look at the reports using something like e.g.:
1435 # opreport -t 0.5 --exclude-dependent
1436 # opreport -t 0.5 /path/to/executable_to_check
1437 # opannotate -t 0.5 --source --assembly
1439 Install ATI's fglrx driver for Xorg / X.org:
1441 Usually there already exist drivers for the grml-system:
1442 # apt-get update ; apt-get install fglrx-driver fglrx-kernel-`uname -r`
1444 After installing adjust xorg.conf via running:
1445 # aticonfig --initial --input=/etc/X11/xorg.conf
1447 For more information take a look at http://wiki.grml.org/doku.php?id=ati
1449 Install nvidia driver for Xorg / X.org:
1451 Usually there already exist drivers for the grml-system:
1452 # apt-get update ; apt-get install nvidia-glx nvidia-kernel-`uname -r`
1454 Then switch from module nv to nvidia:
1456 # sed -i 's/Driver.*nv.*/Driver "nvidia"/' /etc/X11/xorg.conf
1458 glxgears - a GLX demo that draws three rotating gears
1460 To print frames per second (fps) use:
1461 % glxgears -printfps
1463 You forgot to boot with 'grml noeject noprompt' to avoid
1464 ejecting and prompting for CD removal when rebooting/halting
1475 If you want to avoid only the prompting part, run:
1483 Mount wikipedia local via fuse:
1485 Adjust configuration:
1486 % cat ~/.wikipediafs/config.xml
1489 <article-cache-time>300</article-cache-time>
1493 <dirname>wikipedia-de</dirname>
1494 <host>de.wikipedia.org</host>
1495 <basename>/w/index.php</basename>
1498 <dirname>wikipedia-en</dirname>
1499 <host>en.wikipedia.org</host>
1500 <basename>/w/index.php</basename>
1505 Mount it (/wiki must exist of course):
1506 % mount.wikipediafs /wiki
1507 % cat /wiki/wikipedia-en/Cat
1510 % fusermount -u /wiki
1512 Remote notification on X via osd (on screen display):
1514 Start osd_server.py at your local host (listens on port 1234 by default):
1517 Then login to a $REMOTEHOST
1518 % ssh -R 1234:localhost:1234 $REMOTEHOST
1520 Now send the text to your local display via running something like:
1521 % echo "text to send" | nc localhost 1234
1523 Very useful when you are waiting for a long running job
1524 but want to do something else in the meanwhile:
1526 % ./configure && make && echo "finished compiling" | netcat localhost 1234
1528 You can use this in external programs as well of course. Examples:
1530 Use osd in centericq:
1532 % cat ~/.centericq/external
1541 if [ -x /usr/bin/socat -a -x /bin/netcat ] ; then
1542 CONTACT_CUSTOM_NICK=$(cat ${CONTACT_INFODIR}/info | head -n 46 | tail -n 1)
1543 osd_msg="*** CenterICQ: new ${EVENT_NETWORK} ${EVENT_TYPE} from ${CONTACT_CUSTOM_NICK} ***"
1544 if echo | socat - TCP4:localhost:1234 &>/dev/null ; then
1545 echo "${osd_msg}" | netcat localhost 1234
1549 Use it in the IRC console client irssi via running:
1553 You can even activate the port forwarding by default globally:
1558 RemoteForward 1234 127.0.0.1:1234
1561 Notice: if you get 'ABORT: Requested font not found' make sure the
1562 requested font is available, running 'LANG=C LC_ALL=C osd_server.py...'
1565 Avoid automatical startup of init scripts via invoke-rc.d:
1567 First of all make sure the package policyrcd-script-zg2 (which
1568 provides the /usr/sbin/policy-rc.d interface) is installed.
1570 In policyrcd-script-zg2's configuration file named
1571 /etc/zg-policy-rc.d.conf the script /usr/sbin/grml-policy-rc.d is
1572 defined as the interface for handling invoke-rc.d's startup policy.
1574 grml-policy-rc.d can be configure via /etc/policy-rc.d.conf. By
1575 default you won't notice any differences to Debian's default
1576 behaviour, except that invoke-rc.d won't be executed if a chroot has
1577 been detected (detection: /proc is missing).
1579 If you want to disable automatical startup of newly installed packages
1580 (done via the invoke-rc.d mechanism) just set EXITSTATUS to '101' in
1581 /etc/policy-rc.d.conf.
1583 To restore the default behaviour set EXITSTATUS back to '0' in
1584 /etc/policy-rc.d.conf.
1586 Install VMware-Tools for grml:
1588 First of all make sure a CD-ROM device in VMware is available.
1590 Mount the CD-ROM device to /mnt/cdrom, then unpack and install
1594 unp /mnt/cdrom/vmware-linux-tools.tar.gz
1595 cd vmware-tools-distrib
1598 /etc/init.d/networking stop
1603 /etc/init.d/networking start
1605 In an X terminal, launch the VMware Tools running:
1609 Some important Postfix stuff
1617 Send all messages in the queue:
1621 Send all messages in the queue for a specific site:
1625 Delete a specific message
1626 # postsuper -d 12345678942
1628 Deletes all messages held in the queue for later delivery
1629 # postsuper -d ALL deferred
1631 Mail queues in postfix:
1633 incoming -> mail who just entered the system
1634 active -> mail to be delivered
1635 deferred -> mail to be delivered later because there were problems
1636 hold -> mail that should not be delivered until released from hold
1638 For configuration of postfix take a look at
1639 /etc/postfix/master.cf - man 5 master
1640 /etc/postfix/main.cf - man 5 postconf
1641 and http://www.postfix.org/documentation.html.
1645 mode 4000 - set user ID (suid):
1647 - for executable files: run as the user who owns the file, instead of the
1648 user who runs the file
1649 - for directories: not used
1651 mode 2000 - set group ID (guid):
1653 - for executable files: run as the group who owns the file, instead of the
1654 group of the user who runs the file
1655 - for directories: when a file is created inside the directory, it belongs
1656 to the group of the directory instead of the default group of the user who
1659 mode 1000 - sticky bit:
1661 - for files: not used
1662 - for directories: only the owner of a file can delete or rename the file
1664 Create MySQL database
1666 # apt-get install mysql-client mysql-server
1668 Run 'mysql' as root - create a database with:
1670 create database grml
1672 Give a user access to the database (without password):
1674 grant all on grml.* to mika;
1676 Give a user access to the database (with password):
1678 grant all on grml.* to enrico identified by "PASSWORD";
1680 Setup an HTTPS website:
1682 Create a certificate:
1684 # mkdir /etc/apache2/ssl
1685 # make-ssl-cert /usr/share/ssl-cert/ssleay.cnf /etc/apache2/ssl/apache.pem
1687 Create a virtual host on port 443:
1689 <VirtualHost www.foo.invalid:443>
1693 Enable SSL in the VirtualHost:
1696 SSLCertificateFile /etc/apache2/ssl/apache.pem
1698 Enable listening on the HTTPS port (/etc/apache2/ports.conf):
1702 and make sure the SSL module is used:
1706 Useful Apache / Apache2 stuff
1708 Check configuration file via running:
1710 # apache2ctl configtest
1718 # a2enmod modulename
1720 Create tar archive and store it on remote machine:
1722 % tar zcf - /sourcedir | ssh user@targethost "cat >file.tgz"
1724 Pick out and displays images from network traffic:
1728 Install Flash plugin:
1730 # dpkg-reconfigure flashplugin-nonfree
1732 To test a proxy, low level way:
1736 GET http://www.google.com HTTP/1.0 [press enter twice]
1738 Adjust system for use of qemu with kqemu:
1740 Make sure you have all you need:
1741 # aptitude update ; aptitude install qemu kqemu-modules-$(uname -r)
1746 mknod /dev/kqemu c 250 0
1747 chmod 666 /dev/kqemu
1748 chmod 666 /dev/net/tun
1750 Check kqemu support via starting qemu, press
1751 Ctrl-Alt-2 and entering 'info kqemu'.
1753 (High-Load) Debugging related tools:
1755 mpstat # report processors related statistics
1756 iostat # report CPU statistics and input/output statistics for devices and partitions
1757 vmstat # report virtual memory statistics
1758 slabtop # display kernel slab cache information in real time
1759 atsar # system activity report
1760 dstat # versatile tool for generating system resource statistics
1771 Using WPA for network setup manually:
1773 # wpa_supplicant -Dwext -iwlan0 -c/etc/wpa_supplicant.conf
1775 Adjust the options and configuration file to your needs.
1776 Also take a look at 'grml-network'.
1778 Start X and lock console via exiting:
1780 % startx 2>~/.xsession-errors &| exit
1782 Which process is writing to disk and/or causes the disk to spin up?
1784 First of all use lsof to check what's going on. Does not help? ->
1786 # echo 1 > /proc/sys/vm/block_dump
1788 The command sets a sysctl to cause the kernel to log all disk
1789 writes. Please notice that there is a lot of data. So please
1790 disable syslogd/syslog-ng before you do this, or you must make
1791 sure that kernel output is not logged.
1793 When you're done, disable block dump using:
1794 # echo 0 > /proc/sys/vm/block_dump
1797 laptop-mode-tools provides a tool named lm-profiler (laptop mode profiler)
1798 which handles block_dump on its own.
1800 See: $KERNEL-SOURCE/Documentation/laptop-mode.txt
1802 Also take a look at event-viewer(8) which is part of grml-debugtools.
1804 Install initrd via initramfs-tools for currently running kernel:
1806 # update-initramfs -c -t -k $(uname -r)
1808 Install initrd via yaird for currently running kernel:
1810 # yaird -o /boot/initrd.img-$(uname -r)
1812 Install initrd via yaird for specific kernel:
1816 # yaird -o /boot/initrd.img-2.6.15-1-686 2.6.15-1-686
1818 Reinstall package with its original configuration files:
1820 # apt-get install --reinstall -o DPkg::Options::=--force-confmiss -o \
1821 DPkg::Options::=--force-confnew package
1823 grml 0.8 funkenzutzler - rt2x00 drivers:
1825 To avoid conflicts with the other rt2x00-drivers the package rt2x00 (which
1826 includes beta-version drivers) is not installed by default. If you want to
1827 use the kernel modules rt2400pci, rt2500pci, rt2500usb, rt61pci and/or
1828 rt73usb please install the package manually running:
1830 # dpkg -i /usr/src/rt2x00-modules-*.deb
1832 Use Java with jikes and jamvm on grml:
1836 % cp /usr/share/doc/grml-templates/template.java .
1837 % jikes template.java
1840 Notice that grml exports $JIKESPATH (/usr/share/classpath/glibj.zip),
1841 so you do not have to manually run
1842 jikes --bootclasspath /usr/share/classpath/glibj.zip
1844 Online resizing of (Software-)RAID5:
1846 # Initiate a RAID5 setup for testing purposes:
1847 mdadm --create --verbose /dev/md0 --level=5 --raid-devices=3 /dev/hda1 /dev/hdb1 /dev/hdd1
1849 # Create filesystem, mount md0, create a testfile and save md5sum for
1852 mount /dev/md0 /mnt/test
1853 dd if=/dev/urandom of=/mnt/test/dd bs=512 count=10000
1854 md5sum /mnt/test/dd > md5sum
1856 # Make sure the RAID is synched via checking:
1859 # Now remove one partition:
1860 mdadm /dev/md0 --fail /dev/hdd1 --remove /dev/hdd1
1862 # Delete partition, create a new + bigger one and set partition type to fd
1863 # (Linux raid autodetect):
1866 # And re-add the partition:
1867 mdadm -a /dev/md0 /dev/hdd1
1869 # Make sure the RAID is synched via checking:
1872 # Repeat the steps for all other disks/partitions as well:
1873 mdadm /dev/md0 --fail /dev/hdb1 --remove /dev/hdb1
1875 mdadm -a /dev/md0 /dev/hdb1
1877 mdadm /dev/md0 --fail /dev/hda1 --remove /dev/hda1
1879 mdadm -a /dev/md0 /dev/hda1
1882 # Now resize the RAID5 system online [see 'man mdadm' for details]:
1883 mdadm --detail /dev/md0 | grep -e 'Array Size' -e 'Device Size'
1884 mdadm --grow /dev/md0 -z max
1885 mdadm --detail /dev/md0 | grep -e "Array Size" -e 'Device Size'
1887 # Last step - resize the filesystem (online again):
1890 ext3 online resizing:
1892 Starting with Linux kernel 2.6.10 you can resize ext3 online. With
1893 e2fsprogs >=1.39-1 new filesystems are created with directory indexing and
1894 on-line resizing enabled by default (see /etc/mke2fs.conf).
1898 cfdisk /dev/hda # create a partition with type 8e (lvm)
1899 pvcreate /dev/hda2 # create a physical volume
1900 vgcreate resize_me /dev/hda2 # create volume group
1901 lvcreate -n resize_me -L100 resize_me # create a logical volume
1902 mkfs.ext3 /dev/resize_me/resize_me # now create a new filesystem
1903 mount /dev/resize_me/resize_me /mnt/test # mount the new fs for demonstrating online resizing
1904 df -h # check the size of the partition
1905 lvextend -L+100M /dev/resize_me/resize_me # let's extend the logical volume
1906 resize2fs /dev/resize_me/resize_me # and finally resize the filesystem
1907 df -h # recheck the size of the partition
1909 This also works for Software-RAID. Demo:
1911 mdadm --create --verbose /dev/md0 --level=raid1 --raid-devices=2 /dev/hda2 /dev/hdb1
1913 mount /dev/md0 /mnt/test
1914 mdadm /dev/md0 --fail /dev/hda2 --remove /dev/hda2
1915 cfdisk /dev/hda # adjust partition size for hda2
1916 mdadm /dev/md0 --add /dev/hda2
1917 mdadm /dev/md0 --fail /dev/hdb1 --remove /dev/hdb1
1918 cfdisk /dev/hdb # adjust partition size for hdb1
1919 mdadm /dev/md0 --add /dev/hdb1
1920 mdadm --grow /dev/md0 --size=max
1923 Notice: online resizing works as soon as the kernel can re-read the
1924 partition table. So it works for example with LVM and SW-RAID but not with
1925 a plain device (/dev/[sh]d*). The kernel does not re-read the partition
1926 table if the device is already mounted.
1928 Use vim as an outline editor:
1930 % $PAGER /usr/share/doc/vim-vimoutliner/README.Debian
1934 Monitor directories/files for changes using iwatch
1936 Monitor /tmp for changes:
1939 Monitor files/directories specified in /etc/iwatch.xml
1940 and send mail on changes:
1943 Some often used mdadm commands:
1946 # mdadm --create --verbose /dev/md0 --level=raid1 --raid-devices=2 /dev/hda1 /dev/hdb1
1948 Display details of specific RAID:
1949 # mdadm --detail /dev/md0
1952 Simulating a drive failure by software:
1953 # mdadm --manage --set-faulty /dev/md0 /dev/hda1
1955 Remove disk from RAID:
1956 # mdadm /dev/md0 -r /dev/hda1
1958 Set disk as faulty and remove from RAID:
1959 # mdadm /dev/md0 --fail /dev/hda1 --remove /dev/hda1
1964 Restart a RAID-device:
1967 Add another disk to existing RAID setup (hotadd):
1968 # mdadm /dev/md0 -a /dev/hde1
1969 # mdadm --grow /dev/md0 --raid-devices=4
1971 Assemble and start all arrays:
1972 # mdadm --assemble --scan
1974 Assemble a specific array:
1975 # mdadm --assemble /dev/md0 /dev/sda1 /dev/sdb1 /dev/sdc1
1978 # mdadm --assemble --run --force --update=resync /dev/md0 /dev/sda1 /dev/sda2
1981 # mdadm --stop --scan
1983 Scan for and setup arrays automatically:
1984 # mdadm --assemble --scan --auto=yes --verbose
1986 Notice: If the above does not work make sure /etc/mdadm/mdadm.conf contains:
1988 CREATE owner=root group=disk mode=0660 auto=yes
1993 # /usr/share/mdadm/mkconf > /etc/mdadm/mdadm.conf
1996 Monitoring the sw raid
1997 # nohup mdadm --monitor --mail=root@localhost --delay=300 /dev/md0
1999 Producing /etc/mdadm/mdadm.conf:
2000 # mdadm --detail --scan > /etc/mdadm/mdadm.conf
2002 See also: man mdadm | less -p "^EXAMPLES"
2003 http://www.tldp.org/HOWTO/Software-RAID-HOWTO.html
2005 A quick summary of the most commonly used RAID levels:
2008 => 2 disks each 160 GB: 320 GB data
2009 RAID 1: Mirrored Set
2010 => 2 disks each 160 GB: 160 GB data
2011 RAID 5: Striped Set with Parity
2012 => 3 disks each 160 GB: 320 GB data; 160 GB redundancy
2014 Common nested RAID levels:
2015 RAID 01: A mirror of stripes
2016 RAID 10: A stripe of mirrors
2017 RAID 30: A stripe across dedicated parity RAID systems
2018 RAID 100: A stripe of a stripe of mirrors
2020 -- http://en.wikipedia.org/wiki/RAID
2022 Logical Volume Management (LVM) with Linux
2027 | hda1 hdc1 (PV:s on partitions or whole disks)
2033 | usrlv rootlv varlv (LV:s)
2035 | ext3 ext3 xfs (filesystems)
2037 Often used commands:
2038 ~~~~~~~~~~~~~~~~~~~~
2040 Create a physical volume:
2041 # pvcreate /dev/hda2
2043 Create a volume group:
2044 # vgcreate testvg /dev/hda2
2046 Create a logical volume:
2047 # lvcreate -n test_lv -L100 testvg
2049 Resize a logical volume:
2050 # lvextend -L+100M /dev/resize_me/resize_me
2051 # resize2fs /dev/resize_me/resize_me # ext2/3
2052 # xfs_growfs /dev/resize_me/resize_me # xfs
2053 # resize_reiserfs -f /dev/resize_me/resize_me # reiserfs online
2054 # mount -o remount,resize /dev/resize_me/resize_me # jfs
2056 Create a snapshot of a logical volume:
2057 # lvcreate -L 500M --snapshot -n mysnap /dev/testvg/test_lv
2059 Deactivate a volume group:
2060 # vgchange -a n my_volume_group
2062 Actually remove a volume group:
2063 # vgremove my_volume_group
2065 Display information about physical volume:
2066 # pvdisplay /dev/hda1
2068 Remove physical volume:
2069 # vgreduce my_volume_group /dev/hda1
2071 Remove logical volume:
2072 # umount /dev/myvg/homevol
2073 # lvremove /dev/myvg/homevol
2076 http://www.tldp.org/HOWTO/LVM-HOWTO/
2078 How to use APT locally
2080 Sometimes you have lots of packages .deb that you would like to use APT to
2081 install so that the dependencies would be automatically solved. Solution:
2084 dpkg-scanpackages debs /dev/null | gzip > debs/Packages.gz
2085 echo " deb file:/root debs/" >> /etc/apt/sources.list
2086 dpkg-scansources debs | gzip > debs/Sources.gz
2087 echo " deb-src file:/root debs/" >> /etc/apt/sources.list
2089 See also: http://www.debian.org/doc/manuals/apt-howto/ch-basico.en.html
2091 Check filesystem's LABEL:
2094 # vol_id -l /dev/sda1
2096 ext2/3 without vol_id:
2097 # dumpe2fs /dev/sda1 | grep "Filesystem volume name"
2100 # xfs_admin -l /dev/sda1
2102 reiserfs without vol_id:
2103 # debugreiserfs /dev/sda1 | grep -i label
2106 # jfs_tune -l /dev/sda1 | grep -i label
2108 reiser4 without vol_id:
2109 # debugfs.reiser4 /dev/sda1 | grep -i label
2111 Check filesystem's UUID:
2114 # vol_id -u /dev/sda1
2116 ext2/3 without vol_id:
2117 # dumpe2fs /dev/sda1 | grep -i UUID
2120 # xfs_admin -u /dev/sda1
2122 reiserfs without vol_id:
2123 # debugreiserfs /dev/sda1 | grep -i UUID
2125 reiser4 without vol_id:
2126 # debugfs.reiser4 /dev/sda1 | grep -i UUID
2128 Change a filesystem's LABEL:
2131 # mkswap -L $LABEL /dev/sda1
2134 # e2label /dev/sda1 $LABEL
2135 # tune2fs -L $LABEL /dev/sda1
2138 # reiserfstune -l $LABEL /dev/sda1
2141 # jfs_tune -L $LABEL /dev/sda1
2144 # xfs_admin -L $LABEL /dev/sda1
2147 # echo 'drive i: file="/dev/sda1"' >> ~/.mtoolsrc
2148 # mlabel -s i:$LABEL
2151 # ntfslabel $LABEL /dev/sda1
2153 Disable pdiffs feature of APT:
2156 # echo 'Acquire::PDiffs "false";' >> /etc/apt/apt.conf
2159 # apt-get update -o Acquire::Pdiffs=false
2161 Backup big devices or files and create compressed splitted
2162 image chunks of it using zsplit
2164 Create backup of /dev/sda named archiveofsda_#.spl.zp in directory
2165 /mnt/sda1/backup, split the files up into chunks of 1GB each and set
2166 read/write buffer to 256kB:
2167 # zsplit -b 256 -N archiveofsda -o /mnt/sda1/backup/ -s 1G /dev/sda
2169 Restore the backup using unzsplit:
2170 # unzsplit -D /dev/sda -d archiveofsda
2172 More usage examples: man zsplit + man unzsplit
2174 Measure network performance using iperf:
2180 % iperf -c <server_address> -V
2184 Server with 128k TCP window size:
2187 Client with running for 60 seconds and bidirectional test:
2188 % iperf -c <server_address> -r -w128k -t60
2190 Framebuffer resolutions:
2192 Resolution in pixels
2193 Color depth | 640x480 800x600 1024x768 1280x1024
2194 256 (8bit)| 769 771 773 775
2195 32000 (15bit)| 784 787 790 793
2196 65000 (16bit)| 785 788 791 794
2197 16.7 Mill.(24bit)| 786 789 792 795
2201 Mode 0x0300: 640x400 (+640), 8 bits
2202 Mode 0x0301: 640x480 (+640), 8 bits
2203 Mode 0x0303: 800x600 (+800), 8 bits
2204 Mode 0x0303: 800x600 (+832), 8 bits
2205 Mode 0x0305: 1024x768 (+1024), 8 bits
2206 Mode 0x0307: 1280x1024 (+1280), 8 bits
2207 Mode 0x030e: 320x200 (+640), 16 bits
2208 Mode 0x030f: 320x200 (+1280), 24 bits
2209 Mode 0x0311: 640x480 (+1280), 16 bits
2210 Mode 0x0312: 640x480 (+2560), 24 bits
2211 Mode 0x0314: 800x600 (+1600), 16 bits
2212 Mode 0x0315: 800x600 (+3200), 24 bits
2213 Mode 0x0317: 1024x768 (+2048), 16 bits
2214 Mode 0x0318: 1024x768 (+4096), 24 bits
2215 Mode 0x031a: 1280x1024 (+2560), 16 bits
2216 Mode 0x031b: 1280x1024 (+5120), 24 bits
2217 Mode 0x0330: 320x200 (+320), 8 bits
2218 Mode 0x0331: 320x400 (+320), 8 bits
2219 Mode 0x0332: 320x400 (+640), 16 bits
2220 Mode 0x0333: 320x400 (+1280), 24 bits
2221 Mode 0x0334: 320x240 (+320), 8 bits
2222 Mode 0x0335: 320x240 (+640), 16 bits
2223 Mode 0x0336: 320x240 (+1280), 24 bits
2224 Mode 0x033c: 1400x1050 (+1408), 8 bits
2225 Mode 0x033d: 640x400 (+1280), 16 bits
2226 Mode 0x033e: 640x400 (+2560), 24 bits
2227 Mode 0x0345: 1600x1200 (+1600), 8 bits
2228 Mode 0x0346: 1600x1200 (+3200), 16 bits
2229 Mode 0x034d: 1400x1050 (+2816), 16 bits
2230 Mode 0x035c: 1400x1050 (+5632), 24 bits
2232 Portscan using netcat:
2234 # netcat -v -w2 <host|ip-addr.> 1-1024
2236 Run apt-get but disable apt-listchanges:
2238 APT_LISTCHANGES_FRONTEND=none apt-get ...
2240 Upgrade system but disable apt-listbugs:
2242 APT_LISTBUGS_FRONTEND=none apt-get ...
2244 Set up a Transparent Debian Proxy
2246 Install of apt-cacher, the default config will do:
2247 # apt-get install apt-cacher
2249 Check out the ip address of debian mirror(s).
2250 Then add this to your firewall script:
2252 DEBIAN_MIRRORS="141.76.2.4 213.129.232.18"
2253 for ip in ${DEBIAN_MIRRORS} ; do
2254 ${IPTABLES} -t nat -A PREROUTING -s $subnet -d $ip -p tcp --dport 80 -j REDIRECT --to-port 3142
2257 where ${IPTABLES} is the location of your iptables binary
2258 and $subnet is your internal subnet.
2260 Now everybody in your subnet who does access either
2261 ftp.de.debian.org or ftp.at.debian.org will actually
2262 access your apt-cacher instead.
2264 To use apt-cacher on the router itself, add the following
2265 line to your /etc/apt/apt.conf:
2267 Acquire::http::Proxy "http://localhost:3142/";
2269 Version control using Mercurial
2271 Setting up a Mercurial project:
2274 % hg init # creates .hg
2275 % hg add # add all files
2276 % hg commit # commit all changes, edit changelog entry
2278 Branching and merging:
2280 % hg clone linux linux-work # create a new branch
2285 % hg pull ../linux-work # pull changesets from linux-work
2286 % hg merge # merge the new tip from linux-work into
2287 # (old versions used "hg update -m" instead)
2288 # our working directory
2289 % hg commit # commit the result of the merge
2293 % cat ../p/patchlist | xargs hg import -p1 -b ../p
2301 % hg export 1234 > foo.patch # export changeset 1234
2303 Export your current repo via HTTP with browsable interface:
2305 % hg serve -n "My repo" -p 80
2307 Pushing changes to a remote repo with SSH:
2309 % hg push ssh://user@example.com/~/hg/
2311 Merge changes from a remote machine:
2313 host1% hg pull http://foo/
2314 host2% hg merge # merge changes into your working directory
2316 Set up a CGI server on your webserver:
2317 % cp hgwebdir.cgi ~/public_html/hg/index.cgi
2318 % $EDITOR ~/public_html/hg/index.cgi # adjust the defaults
2320 Mercurial repositories of grml can be found at http://hg.grml.org/
2322 Download binary codecs for mplayer:
2324 # /usr/share/mplayer/scripts/win32codecs.sh
2328 # /usr/share/mplayer/scripts/binary_codecs.sh install
2330 (depending on the mplayer version you have).
2332 To play encrypted DVDs and if you are living in a country where using
2333 libdvdcss code is not illegal can install Debian package libdvdread3
2334 and use the script /usr/share/doc/libdvdread3/install-css.sh.
2336 Read manpages of uninstalled packages with debman:
2338 % debman -p git-core git
2340 Test network performance using netperf:
2346 # netperf -t TCP_STREAM -H 192.168.0.41
2348 Setup Xen within 20 minutes on Debian/grml
2350 Install relevant software und update grub's menu.lst (Xen does not work with
2351 usual lilo so install grub instead if not done already):
2353 apt-get install linux-image-2.6.18-1-xen-686 xen-hypervisor-3.0.3-1-i386 \
2354 xen-utils-3.0.3-1 xen-tools bridge-utils
2357 Example for installation of Debian etch as DomU:
2360 xen-create-image --debootstrap --dir=/mnt/md1/xen --size=2Gb --memory=512Mb --fs=ext3 \
2361 --cache=yes --dist=etch --hostname=xengrml1 --ip 192.168.1.2 --netmask 255.255.255.0 \
2362 --gateway 192.168.1.1 --initrd=/boot/initrd.img-2.6.18-1-xen-686 \
2363 --kernel=/boot/vmlinuz-2.6.18-1-xen-686 --mirror=http://ftp.at.debian.org/debian/
2367 /etc/init.d/xend start
2368 /etc/init.d/xendomains start
2370 Setup a bridge for network, either manually:
2372 brctl addbr xenintbr
2373 brctl stp xenintbr off
2374 brctl sethello xenintbr 0
2375 brctl setfd xenintbr 0
2376 ifconfig xenintbr 192.168.1.1 netmask 255.255.255.0 up
2378 or via /etc/network/interfaces (run ifup xenintbr to bring up the device then
2382 iface xenintbr inet static
2383 pre-up brctl addbr xenintbr
2384 post-down brctl delbr xenintbr
2386 netmask 255.255.255.0
2391 Setup forwarding (adjust $PUBLIC_IP; for permanet setup use /etc/sysctl.conf and
2392 add the iptables commands to a startup script like /etc/init.d/rc.local):
2394 echo 1 > /proc/sys/net/ipv4/ip_forward
2395 iptables -t nat -A POSTROUTING -o eth0 -s 192.168.0.0/24 -j SNAT --to $PUBLIC_IP
2396 iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to $PUBLIC_IP
2398 Adjust network configuration of Xend:
2400 cat >> /etc/xen/xend-config.sxp << EOF
2401 (network-script network-route)
2402 (vif-bridge xenintbr)
2403 (vif-script vif-bridge)
2406 List domains, start up a DomU, shutdown later again:
2408 xm create -c /etc/xen/xengrml1.cfg
2412 This HowTo is also available online at http://grml.org/xen/
2414 Play tetris with zsh:
2418 bindkey "^Xt" tetris
2420 Now press 'ctrl-x t'.
2422 Set up a router with grml
2424 Run grml-router script:
2427 Install dnsmasq if not already present:
2428 # apt-get update ; apt-get install dnsmasq
2430 Adjust /etc/dnsmasq.conf according to your needs:
2431 # cat >> /etc/dnsmasq.conf << EOF
2434 dhcp-range=19.168.0.124,192.168.0.254,1m # dhcp range
2435 dhcp-option=3,192.168.0.1 # dns server
2436 dhcp-option=1,255.255.255.0 # netmask
2439 Start dnsmasq finally:
2442 Display stats about memory allocations performed by a program:
2444 Usage example for 'ls':
2446 % LD_PRELOAD=/lib/libmemusage.so ls > /dev/null
2448 Use KVM (Kernel-based Virtual Machine for Linux):
2450 Make sure to install the relevant tools:
2451 # apt-get update ; apt-get install kvm
2454 Test it with a minimal system like ttylinux:
2455 # wget http://www.minimalinux.org/ttylinux/packages/bootcd-i386-5.3.iso.gz
2456 # gzip -d bootcd-i386-5.3.iso.gz
2457 # kvm -cdrom bootcd-i386-5.3.iso
2459 EEPROM data decoding for SDRAM DIMM modules:
2462 # /usr/share/doc/lm-sensors/examples/eeprom/decode-dimms.pl
2466 Make sure your device is supported by Linux and running.
2467 See http://www.linuxtv.org/ for more details.
2469 If the DVB device works on your system (see 'hwinfo --usb'
2470 when using a DVB usb device for example), then make sure you
2471 have the scan util from dvb-utils available:
2473 # aptitude install dvb-utils
2475 Then create a channels.conf configuration file:
2477 % scan /usr/share/doc/dvb-utils/examples/scan/... > ~/.mplayer/channels.conf
2479 You can find some example configuration files on
2480 your grml system in ~/.channels. Usage example:
2482 % ln -s ~/.mplayer/channels.conf-AT-graz ~/.mplayer/channels.conf
2484 Tip: w_scan (see http://free.pages.at/wirbel4vdr/w_scan/index2.html)
2485 might be useful if you do not know the initial configuration
2488 Get the lastest mercurial snapshot:
2490 Make sure you have the python-dev package available:
2491 # apt-get update ; apt-get install python-dev
2493 Get and build the source:
2494 % hg clone http://selenic.com/repo/hg mercurial
2497 % export PYTHONPATH=$(pwd)
2498 % export PATH=$PATH:$(pwd)
2500 now you should have the newest version of mercurial whenever you execute hg.
2502 To update to the lastest development snapshot, additionally use
2503 the following commands:
2504 % hg pull -u http://hg.intevation.org/mercurial/crew
2510 Available bootoptions relevant in live-cd mode:
2511 -----------------------------------------------
2513 * utc: set UTC, if your system clock is set to UTC (GMT)
2514 * gmt: set UTC, if your system clock is set to UTC (GMT) [like bootoption utc]
2515 * tz=$option: set timezone to corresponding $option, usage example:
2518 Configuration options relevant on harddisk installation:
2519 --------------------------------------------------------
2521 * Use the tzconfig utility to set the local timezone:
2525 which adjusts /etc/timezone and /etc/localtime according
2526 to the provided information. Running:
2528 # dpkg-reconfigure tzdata
2530 might be useful as well.
2532 * /etc/default/rcS: set variable UTC according to your needs,
2533 whether your system clock is set to UTC (UTC='yes') or
2536 * /etc/localtime: adjust zoneinfo according to your needs:
2538 # ln -sf /usr/share/zoneinfo/$WHATEVER_YOU_WANT /etc/localtime
2540 The zoneinfo directory contains the time zone files that were
2541 compiled by zic. The files contain information such as rules
2542 about DST. They allow the kernel to convert UTC UNIX time into
2543 appropriate local dates and times. Use the zdump utility to
2544 print current time and date (in the specified time zone).
2546 * /etc/adjtime: This file is used e.g. by the adjtimex function,
2547 which can smoothly adjust system time while the system runs
2549 * If you change the time (using 'date --set ...', ntpdate,...)
2550 it is worth setting also the hardware clock to the correct time:
2552 # hwclock --systohc [--utc]
2554 Remember to add the --utc -option if the hardware clock is set
2560 Check your current settings via:
2563 zdump /etc/localtime
2566 grep hwclock /etc/runlevel.conf
2567 grep '^UTC' /etc/default/rc
2569 Further information:
2570 --------------------
2572 hwclock(8) tzselect(1) tzconfig(8)
2573 http://www.debian.org/doc/manuals/system-administrator/ch-sysadmin-time.html
2574 http://wiki.debian.org/TimeZoneChanges
2576 Recorder shellscript session using script:
2578 % script -t 2>~/upgrade.time -a ~/upgrade.script
2579 % scriptreplay ~/upgrade.time ~/upgrade.script
2581 Test UTF-8 capabilities of terminal:
2583 wget http://melkor.dnp.fmph.uniba.sk/~garabik/debian-utf8/download/UTF-8-demo.txt.gz
2584 zcat UTF-8-demo.txt.gz
2588 wget http://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-test.txt
2591 UTF-8 at grml / some general information regarding Unicde/UTF-8:
2593 http://wiki.grml.org/doku.php?id=utf8
2596 This allows one ssh connection attepmt per minute per source ip, with a initial
2597 burst of 10. The available burst is like a counter which is initialised with
2598 10. Every connection attempt decrements the counter, and every minute where the
2599 connection limit of one per minute is not overstepped the counter is
2600 incremented by one. If the burst counter is exhausted the real rate limit
2601 comes into play. This gives you 11 connectionattepmts in the first minute
2602 before blocked for 10minutes. After 10 minutes block the game restarts.
2604 Hint: you could set the burst value to 5 and the block time to only 5 minutes
2605 to achive the same average connection rate but with halve the block time.
2607 iptables -A inet_in -p tcp --syn --dport 22 -m hashlimit --hashlimit-name ssh \
2608 --hashlimit 1/minute \ --hashlimit-burst 10 --hashlimit-mode srcip \
2609 --hashlimit-htable-expire 600000 -j ACCEPT
2610 iptables -A inet_in -p tcp --dport 22 -m state --state NEW -j REJECT
2612 Tunnel a specific connection via socat:
2615 % socat TCP4-LISTEN:8003 TCP4:gateway:500
2618 # socat TCP4-LISTEN:500,fork TCP4:target:$PORT
2620 Using localhost:8003 on the client uses the tunnel now.
2624 # date --set=060916102007
2626 where the bits are month(2)/day(2)/hour(2)/minute(2)/year(4)
2628 Set date using a relative date:
2634 # date -s '+tomorrow'
2636 Display a specific relative date:
2638 # date -d '+5 days -2 hours'
2640 Don't forget to set hardware clock via:
2644 Booting grml via network / PXE:
2646 Start grml-terminalserver on a system with network access
2647 and where grml is running:
2649 # grml-terminalserver
2651 Then booting your client(s) via PXE should work without
2654 Debugging SSL communications:
2656 % openssl s_client -connect server.adress:993
2660 # ssldump -a -A -H -i eth0
2662 See http://prefetch.net/articles/debuggingssl.html for more details.
2664 Remove bootmanager from MBR:
2666 # lilo -M /dev/hda -s /dev/null
2668 Rewrite grub to MBR:
2671 # grub-install --recheck --no-floppy --root-directory=/mnt/sda1 /dev/sda
2673 Rewrite lilo to MBR:
2678 Create screenshot of plain/real console - tty1:
2680 # fbgrab -c 1 screeni.png
2682 Create screenshot when running X:
2686 Tip: use the gkrellshoot plugin when using gkrellm
2688 Redirect all connections to hostA:portA to hostB:portB, where hostA and hostB are
2691 Run the following commands on hostA:
2693 echo 1 > /proc/sys/net/ipv4/ip_forward
2694 iptables -t nat -A PREROUTING -p tcp --dport portA -j DNAT --to hostB:portB
2695 iptables -A FORWARD -i eth0 -o eth0 -d hostB -p tcp --dport portB -j ACCEPT
2696 iptables -A FORWARD -i eth0 -o eth0 -s hostB -p tcp --sport portB -j ACCEPT
2697 iptables -t nat -A POSTROUTING -p tcp -d hostB --dport portB -j SNAT --to-source hostA
2699 Flash BIOS without DOS/Windows:
2701 Dump flash info and set the flash chip to writable:
2704 Backup the original BIOS:
2705 # flashrom -r backup.bin
2707 Notice: the following step will overwrite your current BIOS!
2708 So make sure you really know what you are doing.
2710 Flash the BIOS image:
2711 # flashrom -wv newbios.bin
2713 Also check out LinuxBIOS: http://linuxbios.org/
2715 Enable shadow passwords:
2719 Set up an IPv6 tunneln on grml:
2723 Set up console newsreader slrn for use with Usenet:
2727 Calculate with IPv6 addresses:
2731 For usage examples refer to manpage ipv6calc(8).
2733 Common network debugging tools for use with IPv6:
2742 Set up NFS (Network File System):
2746 Make sure the relevant services are running on the server side:
2748 # /etc/init.d/portmap start
2749 # /etc/init.d/nfs-common start
2750 # /etc/init.d/nfs-kernel-server start
2752 Export shares via /etc/exports:
2754 /backups 192.168.1.100/24(rw,wdelay,no_root_squash,async,subtree_check)
2756 ... or manually export a directory running:
2758 # exportfs -o rw,wdelay,no_root_squash,async,subtree_check 192.168.1.100:/backups
2760 and unexport a share running:
2762 # exportfs -u 192.168.1.100:/backups
2764 and every time when you modify /etc/exports file run
2768 Display what NFS components are running:
2772 Display list of exported shares:
2780 Make sure the relevant services are running on the client side:
2782 # /etc/init.d/portmap start
2783 # /etc/init.d/nfs-common start
2785 Verify that the server allows you to access its RPC/NFS services:
2787 # rpcinfo -p server_name
2789 Check what directories the server exports:
2791 # showmount -e server_name
2793 On the client side you can use something like the following in /etc/fstab:
2795 192.168.1.101:/backups /mnt/nfs nfs defaults,users,wsize=8192,rsize=8192 0 0
2799 # aptitude install cloop-src
2802 # modprobe cloop file=/path/to/cloop/file
2803 # mount -r -t iso9660 /dev/cloop /mnt/test
2805 Create a PS/PDF of a plaintext file:
2807 % a2ps --medium A4dj -E -o output.ps input_file
2810 Print two pages on one in a PDF file:
2812 % pdfnup --nup 2x1 input.pdf
2814 Concatenate, extract pages/parts, encrypt/decrypt,
2815 compress PDFs using 'pdftk'.
2817 Read a PS/PDF file on console:
2821 or on plain framebuffer console in graphical mode:
2823 % pdf2ps file.pdf ; ps2png file.ps file.png ; fbi file.png
2829 Bypass the password of a PDF file:
2831 % gs -q -dNOPAUSE -sDEVICE=pdfwrite -sOutputFile=output.pdf input.pdf -c quit
2837 This will record a AIFF audio file.