Add SysRq Keys, Memcheck/memtest

[grml-tips.git] / grml_tips

diff --git a/grml_tips b/grml_tips
index 52bb33d..225862e 100644 (file)
--- a/grml_tips
+++ b/grml_tips
@@ -657,7 +657,7 @@ to get a list of all supported trees
 -- 
 Transfer your SSH public key to another host:
 
-% ssh-keygen   # if you don't have a key yet
+% ssh-keygen   # ssh-keygen / ssh-key-gen: if you don't have a key yet
 [...]
 % ssh-copy-id -i ~/.ssh/id_rsa.pub user@remote-system
 or
@@ -2847,6 +2847,12 @@ Create netboot package for grml-terminalserver:
 
 # sh /usr/share/doc/grml-terminalserver/examples/create-netboot
 -- 
+To boot grml via network (PXE) check out grml-terminalserver:
+
+# grml-terminalserver
+
+See http://grml.org/terminalserver/ for more details.
+-- 
 Rotate pictures:
 
 Using the 'Orientation' tag of the Exif header, rotate
@@ -2867,3 +2873,60 @@ This will rename a file named img_2071.jpg to something like:
 if it was shot at 10:38 o'clock on 2007-08-17 (according to
 the information inside the exif header).
 -- 
+Calculate network / netmask:
+
+Usage examples:
+% ipcalc 10.0.0.28 255.255.255.0
+% ipcalc 10.0.0.0/24
+-- 
+Blacklist a kernel module:
+
+# blacklist <name_of_kernel_module>
+
+-> running 'blacklist hostap_cs' for example will generate an
+entry like this in /etc/modprobe.d/grml:
+
+blacklist hostap_cs
+alias hostap_cs off
+
+To remove the module from the blacklist again just invoke:
+
+# unblacklist <name_of_kernel_module>
+
+or manually remove the entry from /etc/modprobe.d/grml.
+-- 
+Create a Debian package of a perl module:
+
+% dh-make-perl --cpan Acme::Smirch --build
+-- 
+The Magic SysRq Keys (SysReq or Sys Req, short for System Request):
+
+To reboot your system using the SysRq keys just hold down the Alt and
+SysRq (Print Screen) key while pressing the keys REISUB ("Raising
+Elephants Is So Utterly Boring").
+
+R = take the keyboard out of raw mode
+E = terminates all processes (except init)
+I = kills all processes (except init)
+S = synchronizes the disk(s)
+U = remounts all filesystems read-only
+B = reboot the system
+
+Notice: use O instead of B for poweroff.
+
+Or write the sequence to /proc/sysrq-trigger instead:
+
+# for i in r e i s u b ; do echo $i > /proc/sysrq-trigger ; done
+
+To enable or disable SysRq calls:
+
+# echo 0 > /proc/sys/kernel/sysrq
+# echo 1 > /proc/sys/kernel/sysrq
+
+See http://en.wikipedia.org/wiki/Magic_SysRq_key for more details.
+-- 
+Memtest / memcheck:
+
+Just boot your grml Live-CD with "memtest" to execute a memcheck/memtest
+with Memtest86+.
+--