On Wednesday 10 December 2008, John wrote:
On Tue, 2008-12-09 at 12:07 -0500, Ross Walker wrote:
On Dec 9, 2008, at 10:59 AM, Matt lm7812@gmail.com wrote:
Setting scheduler is global in C4 it can be set as a kernel option with a scheduler=deadline in grub.
Is that an alias for "elevator=deadline" (which I know works)?
No that was me forgetting the option name.
Thanks Peter, it's elevator= not scheduler=
Does this mean I need to add "elevator=deadline" to grub.conf? Is there a way to make the change without rebooting?
I'm afraid not, so possibly a late night or weekend event with the option for a mid day reboot to recover if things turn out badly.
Virtualize things and you can minimize downtime with snapshots.
[root@blah ~]# cat /sys/block/hda/queue/scheduler noop anticipatory deadline [cfq] The Schedular is CFQ and can be changed on the fly to whatever Block Device you want it.
...
[root@blah ~]# echo 'deadline' > /sys/block/hda/queue/scheduler [root@blah ~]# cat /sys/block/hda/queue/scheduler noop anticipatory [deadline] cfq -- Changed to Deadline.
...this is correct on CentOS-5. On CentOS-4 you need to do it via grub and a reboot.
/Peter