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Linux Kernel Notes

Thu, 08/19/2010 - 15:44 — vsaadmin

This page has a collection of bits and ideas useful when you HAVE to tame the Linux Kernel. Enjoy! Check the Scheduler choices and Active Scheduler: anand@laptop-aries5672:~$ cat /sys/block/sda/queue/scheduler noop anticipatory deadline [cfq] A list of parameters you can provide to Linux Kernel during installation or bootup to change Linux's behaviour.

Parameter What it does Distro Notes
nousb Disable USB support All Post-install
acpi=off Turn off acpi All Use this if your installer or OS hangs without any error messages
Number such as 1 2 3 4 5 Select the runlevel to boot into All  
elevator={cfq | deadline} Pick the I/O scheduler All cfq suitable for desktops, deadline for servers
reboot=warm Quick reboot All  
mce=off Turn off Machine Check Exceptions All  
nostorage Turn off Detecting additional storage (eg: FC HBA/SANs) All  

and to make these persist across reboots, append the following to /etc/sysctl.conf

Turn off OOM killer echo 0 > /proc/sys/vm/oom-kill All /etc/sysctl.conf: vm.oom-kill = 0
To reboot 5 secs after panic echo 5 > /proc/sys/kernel/panic All /etc/sysctl.conf: kernel.panic = 5

To increase the number of loop devices from 7 (default) to 32: add, max_loop=32 into /etc/modprobe.conf and unload and reload the cloop device