Am Montag, 7. Mai 2012 schrieb Stefan Priebe - Profihost AG: > > iostat -x -d -m 5 and vmstat 5 traces would be > > useful to see if it is your array that is slow..... > > ~ # iostat -x -d -m 5 > Linux 2.6.40.28intel (server844-han) 05/07/2012 _x86_64_ > (8 CPU) > > Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s > avgrq-sz avgqu-sz await svctm %util > sdb 0,00 0,00 254,80 25,40 1,72 0,16 > 13,71 0,86 3,08 2,39 67,06 > sda 0,00 0,20 0,00 1,20 0,00 0,00 > 6,50 0,00 0,00 0,00 0,00 > > Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s > avgrq-sz avgqu-sz await svctm %util > sdb 0,00 0,00 187,40 24,20 1,26 0,19 > 14,05 0,75 3,56 3,33 70,50 > sda 0,00 0,00 0,00 0,40 0,00 0,00 > 4,50 0,00 0,00 0,00 0,00 > > Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s > avgrq-sz avgqu-sz await svctm %util > sdb 0,00 11,20 242,40 92,00 1,56 0,89 > 15,00 4,70 14,06 1,58 52,68 > sda 0,00 0,20 0,00 2,60 0,00 0,02 > 12,00 0,00 0,00 0,00 0,00 > > Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s > avgrq-sz avgqu-sz await svctm %util > sdb 0,00 0,00 166,20 24,00 0,99 0,17 > 12,51 0,57 3,02 2,40 45,56 > sda 0,00 0,00 0,00 0,00 0,00 0,00 > 0,00 0,00 0,00 0,00 0,00 > > qDevice: rrqm/s wrqm/s r/s w/s rMB/s wMB/s > avgrq-sz avgqu-sz await svctm %util > sdb 0,00 0,00 188,00 25,40 1,22 0,16 > 13,23 0,44 2,04 1,78 38,02 > sda 0,00 0,00 0,00 0,00 0,00 0,00 > 0,00 0,00 0,00 0,00 0,00 Disk utilization seems to be quite high but it seems there not near to 90 to 100%. So there might be other overheads involved - like network or (unlikely) CPU. Did you verify that at the time you perceive slowness the servers you backup can deliver data fast enough? I would like to now, whether there are really processes waiting for I/O during rsync workload. Can you try vmstat 5 and while true; do ps aux | grep " D" | grep -v grep ; sleep 1; done while the backup workload is running and slow? Like this: merkaba:~> while true; do ps aux | grep " D" | grep -v grep ; sleep 1; done root 1508 0.0 0.0 0 0 ? D Mai06 0:00 [flush-253:2] root 1508 0.0 0.0 0 0 ? D Mai06 0:00 [flush-253:2] martin 28374 100 0.0 9800 652 pts/7 D+ 10:27 0:02 dd if=/dev/zero of=fhgs root 1508 0.0 0.0 0 0 ? D Mai06 0:00 [flush-253:2] (this is with an Ext4, so its using the flush daemon, with XFS you probably see xfssyncd or xfsbufd instead if I am not mistaken and if rsync processes are waiting for I/O they should appear there too) And yes, its important to have vmstat 5 output during workload is happening to see the amount of CPU time that the kernel cannot use for processing cause all processes that are runnable wait for I/O. -- Martin 'Helios' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7 _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
