X-Git-Url: http://git.grml.org/?a=blobdiff_plain;f=grml_tips;h=4fa526361d41e0573e0c2fbaf905600fa4fb113c;hb=4c8e7332cd1a7b92a85de64d90273ad5845821df;hp=9972eef6854804eb6dfd52569a18d8aeedf6df7b;hpb=b90b7d7c4405083bf772a1c67e68760cb72fb5ac;p=grml-tips.git diff --git a/grml_tips b/grml_tips index 9972eef..4fa5263 100644 --- a/grml_tips +++ b/grml_tips @@ -3006,3 +3006,85 @@ Hints: - Do not use interface names without ending 0 (otherwise startup fails). - Only chooss unique names for interfaces. -- +Find dangling symlinks using zsh: + +% ls **/*(-@) +-- +Use approx with runit supervision +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Install the packages: +# apt-get install approx runit + +Add user approxlog for the logging daemon: +# adduser --system --home /nonexistent --no-create-home approxlog + +Create config directory: +# mkdir /etc/sv/approx + +Use /var/run/sv.approx as supervise directory: +# ln -s /var/run/sv.approx /etc/sv/approx/supervise + +# cat > /etc/sv/approx/run << EOF +#!/bin/sh +echo 'approx starting' +exec approx -f 2>&1 +EOF + +You normally do not need a logging service for approx because it logs +to syslog too. So just for completion: +# mkdir -p /etc/sv/approx/log +# ln -s /var/run/sv.approx.log /etc/sv/approx/log/supervise +# cat > /etc/sv/approx/log/run << EOF +#!/bin/sh +set -e +LOG="/var/log/approx" +test -d "$LOG" || mkdir -p -m2750 "$LOG" && chown approxlog:adm "$LOG" +exec chpst -uapproxlog svlogd -tt -v "$LOG" +EOF + +Now activate the new approx service (will be started within 5s): +# ln -s /etc/sv/approx/ /var/service/ + +Make approx managed via runit available via init-script interface: +# dpkg-divert --local --rename /etc/init.d/approx +# ln -s /usr/bin/sv /etc/init.d/approx +-- +Remote-reboot a grml system using SysRQ via /proc (execute as root): + +eject &>/dev/null +umount -l /cdrom +eject /dev/cdrom +echo b > /proc/sysrq-trigger +-- +Show what happens on /dev/sda0: + +# mount the debugfs to relay kernel info to userspace +mount -t debugfs none /sys/kernel/debug + +# is a convenient wrapper arround blktrace and blkparse +btrace /dev/sda0 +-- +Convert Flash to Avi: + +% ffmpeg -i input.flv output.avi +-- +Usage example for cryptsetup / -luks encrypted partition on LVM: + +volume group name: x61 +logical volume name: home + +echo "grml-crypt_home /dev/mapper/x61-home none luks" >> /etc/crypttab +Start cryptdisks +mount /dev/mapper/grml-crypt_home /mnt/test +-- +fdisk/parted/... complains with something like +'unable to open /dev/sda - unrecognised disk label'?! + +See http://grml.org/faq/#fdisk => + +* use /sbin/fdisk.distrib from util-linux +* switch to sfdisk, cfdisk,... +* use parted's mklabel command (but please read the + parted manual before executing this command) +--