Hello, I''ve seen from time to time where a domU using heavy disk I/O can slow down an entire server (including all other domU''s and dom0). Is there a way to schedule or limit this in Xen 3.0.3? Thank you, Brian ** _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 9/10/06 5:30 am, "Brian Hays" <brian.hays@gmail.com> wrote:> I''ve seen from time to time where a domU using heavy disk I/O can slow down an > entire server (including all other domU''s and dom0). Is there a way to > schedule or limit this in Xen 3.0.3?You should be able to use the CFQ I/O scheduler in domain0 to set per-domain scheduling parameters. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Hi Keir, I''m using the kernel option "elevator=cfq" on both dom0 and domU''s. However, the output of "cat /sys/block/sda1/queue/scheduler" within a domU is still "[noop] anticipatory deadline cfq". Does this mean that cfq is NOT being used even though the dmesg shows "io scheduler cfq registered (default)". ...dom0 shows "noop anticipatory deadline [cfq]" Thank you, Brian On 10/9/06, Keir Fraser <Keir.Fraser@cl.cam.ac.uk> wrote:> > On 9/10/06 5:30 am, "Brian Hays" <brian.hays@gmail.com> wrote: > > I''ve seen from time to time where a domU using heavy disk I/O can slow > down an entire server (including all other domU''s and dom0). Is there a way > to schedule or limit this in Xen 3.0.3? > > > You should be able to use the CFQ I/O scheduler in domain0 to set > per-domain scheduling parameters. > > -- Keir >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
> I''m using the kernel option "elevator=cfq" on both dom0 and domU''s. > However, the output of "cat /sys/block/sda1/queue/scheduler" within adomU> is still "[noop] anticipatory deadline cfq". Does this mean that cfqis NOT> being used even though the dmesg shows "io scheduler cfq registered > (default)". > > ...dom0 shows "noop anticipatory deadline [cfq]"That means you''re using cfq in dom0, which is what you want. Now you can use ''ionice'' to control scheduling from different domU block devices. It doesn''t matter what you use in domU, noop is fine. Ian _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
hi, Am Montag, 9. Oktober 2006 20:47 schrieb Ian Pratt: [..]> > ...dom0 shows "noop anticipatory deadline [cfq]" > That means you''re using cfq in dom0, which is what you want. Now you can > use ''ionice'' to control scheduling from different domU block devices. > It doesn''t matter what you use in domU, noop is fine.i think any other than noop is a waste of time in a domU because the block device inside domU is "virtual" and io scheduling is only advantageous with real block devices with a high seek time like hard disks. -- greetings eMHa _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel