Hi all,
I just installed centos 5.4 xen-kernel on intel core i5 machine as dom0. After some hours of syncing a raid10 array (8 sata disk) I noticed a steadily increasing loadavg. I think without reasonable i/o wait or cpu utilization the loadavg on this system should be very lower. If this loadavg is normal I would be greatful if somone could explain why. The screenshots below show that there is neither much i/o wait nor much cpu utilization.
top - 09:10:25 up 9:26, 1 user, load average: 7.24, 7.63, 7.72 Tasks: 116 total, 4 running, 112 sleeping, 0 stopped, 0 zombie Cpu0 : 0.0%us, 42.5%sy, 0.0%ni, 57.5%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu1 : 0.0%us, 1.3%sy, 0.0%ni, 97.7%id, 0.0%wa, 0.0%hi, 0.0%si, 1.0%st Cpu2 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu3 : 0.0%us, 10.0%sy, 0.0%ni, 89.0%id, 0.0%wa, 0.0%hi, 0.0%si, 1.0%st Mem: 7805952k total, 809612k used, 6996340k free, 112092k buffers Swap: 0k total, 0k used, 0k free, 341304k cached
[root@vserver ~]# iostat -d -x sda sdb sdc sdd sde sdf sg sdh Linux 2.6.18-164.6.1.el5xen (vserver.zimmermann.com) 20.11.2009
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util sda 1364,57 0,66 1820,12 0,89 25477,44 12,37 14,00 1,11 0,61 0,41 75,10 sdb 1167,12 0,68 2017,45 0,89 25476,53 12,47 12,63 1,16 0,57 0,39 79,49 sdc 1308,06 0,66 1876,65 0,91 25477,64 12,50 13,58 1,14 0,61 0,42 78,73 sdd 1267,27 0,66 1917,28 0,92 25476,32 12,57 13,29 1,09 0,57 0,42 80,16 sde 1146,76 0,63 2037,99 0,87 25477,94 11,96 12,50 0,98 0,48 0,31 63,80 sdf 1126,88 0,64 2057,62 0,87 25475,99 12,02 12,38 1,08 0,52 0,34 69,89 sdh 472,21 0,66 2712,31 0,92 25476,13 12,43 9,39 0,66 0,24 0,15 41,03
[root@vserver ~]# cat /proc/loadavg 7.22 7.58 7.69 8/129 23348
Best regards, Günter Zimmermann
On 11/20/2009 09:13 AM, Günter Zimmermann wrote:
Hi all,
I just installed centos 5.4 xen-kernel on intel core i5 machine as dom0. After some hours of syncing a raid10 array (8 sata disk) I noticed a steadily increasing loadavg. I think without reasonable i/o wait or cpu utilization the loadavg on this system should be very lower. If this loadavg is normal I would be greatful if somone could explain why. The screenshots below show that there is neither much i/o wait nor much cpu utilization.
top - 09:10:25 up 9:26, 1 user, load average: 7.24, 7.63, 7.72 Tasks: 116 total, 4 running, 112 sleeping, 0 stopped, 0 zombie Cpu0 : 0.0%us, 42.5%sy, 0.0%ni, 57.5%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu1 : 0.0%us, 1.3%sy, 0.0%ni, 97.7%id, 0.0%wa, 0.0%hi, 0.0%si, 1.0%st Cpu2 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu3 : 0.0%us, 10.0%sy, 0.0%ni, 89.0%id, 0.0%wa, 0.0%hi, 0.0%si, 1.0%st Mem: 7805952k total, 809612k used, 6996340k free, 112092k buffers Swap: 0k total, 0k used, 0k free, 341304k cached
[root@vserver ~]# iostat -d -x sda sdb sdc sdd sde sdf sg sdh Linux 2.6.18-164.6.1.el5xen (vserver.zimmermann.com) 20.11.2009
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util sda 1364,57 0,66 1820,12 0,89 25477,44 12,37 14,00 1,11 0,61 0,41 75,10 sdb 1167,12 0,68 2017,45 0,89 25476,53 12,47 12,63 1,16 0,57 0,39 79,49 sdc 1308,06 0,66 1876,65 0,91 25477,64 12,50 13,58 1,14 0,61 0,42 78,73 sdd 1267,27 0,66 1917,28 0,92 25476,32 12,57 13,29 1,09 0,57 0,42 80,16 sde 1146,76 0,63 2037,99 0,87 25477,94 11,96 12,50 0,98 0,48 0,31 63,80 sdf 1126,88 0,64 2057,62 0,87 25475,99 12,02 12,38 1,08 0,52 0,34 69,89 sdh 472,21 0,66 2712,31 0,92 25476,13 12,43 9,39 0,66 0,24 0,15 41,03
[root@vserver ~]# cat /proc/loadavg 7.22 7.58 7.69 8/129 23348
Does the process list show anything out of the ordinary? You can get a bogus load indication if you have mounted a nfs share, turn the server off and do a couple of "ls <nfs mountpoint>" for example. In that case each ls process will hang and drive up the load even though they don't actually cause any cpu/io pressure on the system.
Regards, Dennis
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Dennis J. -
Günter Zimmermann