Reboot

emergency reboot a hung Linux host

Sometimes you need something that can kick a host a bit harder than the standard reboot command. Even if you include the -f switch to force, a hung task can prevent your host from rebooting.

Try this - first enable the sysrq setting, then trigger. Your host should reboot immediately.

sudo echo 1 > /proc/sys/kernel/sysrq
sudo echo b > /proc/sysrq-trigger

Note : This is effectively a hard reset which does not cleanly shut services or tasks down. You may need to check your disk on some operating systems.

opensolaris - smbd issues?

Hmm… i’ve been having problems since the 2009.06 (snv_111b) update with cifs.

Cant pin it exactly as it could be “load” related… hmmm.

found this ? http://opensolaris.org/jive/thread.jspa?threadID=107681 this also may be a clue.. http://opensolaris.org/jive/thread.jspa?threadID=92472&tstart=75

imapd ?  might have to go back to 2008.11

You might get better performance if you enable oplocks but there are known issues with it but you can do it just to see if you see any difference:

svccfg -s smb/server setprop smbd/oplock_enable=boolean: true

Linux - crontab

Time to schedule some tasks!

First you need to make sure your in the /etc/cron.d/cron.allow file. If you are not SU to root and add yourself into it.

Now to create your new crontab file;

crontab -e

You are in vi in your newly created crontab file (note if you do not have access to do this it will say so)

Now, i’m no expert at using vi, but if you press i you will go into insert mode. Do this, then type the cron job details. A typical cron job will look like this