Israel Garcia
2010-May-17 05:40 UTC
[Xen-users] ionice command to set i/o priorities for domUs
Hi, I have xen on a debian lenny with more then 20 VM. The supermicro server has a raid10 with a good performance, but I have IO issues when one VM is making backup, it affects the performance of the other VMs. I''ve setup cpus, vcpus, sched-credit between dom0 and domUs as doc recommended, but I''m still facing IO problems. So I found a way to mediate disk access with ionice from the dom0. I mean changing priority to domUs PID. See below more details. I''m using CFQ scheduler dom0:~# cat /sys/block/[sh]d[a-z]*/queue/scheduler noop anticipatory deadline [cfq] noop anticipatory deadline [cfq] It''s a part of ps regarding block devices: 15747 ? S< 0:00 \_ [blkback.64.xvda] 15748 ? S< 0:54 \_ [blkback.64.xvda] 20353 ? S< 0:00 \_ [blkback.71.xvda] 20354 ? S< 0:05 \_ [blkback.71.xvda] 2361 ? S< 0:00 \_ [blkback.112.xvd] 2362 ? S< 0:15 \_ [blkback.112.xvd] 26596 ? S< 0:00 \_ [blkback.122.xvd] 26597 ? S< 0:00 \_ [blkback.122.xvd] 27203 ? S< 0:00 \_ [blkback.123.xvd] 27204 ? S< 0:00 \_ [blkback.123.xvd] Finally, I change these PIDs with ionice and make several tests but I''m still confuse with the results. My question: Does anybody on this list use ionice to mediate disk priority to disk intense domU with ionice from dom0? appreciate your help. -- Regards; Israel Garcia _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users