* Large IO Waits for srm.
@ 2005-04-10 7:07 Nicholas Lee
0 siblings, 0 replies; 2+ messages in thread
From: Nicholas Lee @ 2005-04-10 7:07 UTC (permalink / raw)
To: xen-devel
I've got four VMs running including dom0, on U320 SCSI md-raid1.
In domO I'm srm (secure delete) a couple 600Mb+ files. The other domUs are idle.
Xen 2.0.6-testing/2.6.11.6
nic@sea:/backup$ vmstat 3
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
3 1 4 1976 32 97020 0 0 193 1811 341 512 0 6 23 71
0 1 4 2136 32 96836 0 0 3 2507 440 650 0 1 0 99
0 1 4 2104 32 96872 0 0 0 2571 431 664 0 0 0 100
0 1 4 2104 32 96868 0 0 0 2561 432 668 0 0 0 100
0 1 4 2200 32 96792 0 0 37 2379 419 656 0 0 0 100
...
nic@sea:/backup$ w
17:26:16 up 4:21, 1 user, load average: 1.00, 1.00, 0.92
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
nic pts/1 base-one.kiwa.co 17:22 0.00s 0.01s 0.00s w
The large IO wait level seems more than it should be. Here is an IDE
based non Xen system doing the same.
nic@lode:/home/bak$ vmstat 3
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
0 1 41984 57352 5856 352988 0 0 3 4 1 2 1 0 98 1
1 1 41984 56264 5880 353000 0 0 1 24937 2584 5174 1 29 0 69
1 0 41984 56264 5880 353020 0 0 0 6161 1417 1073 0 81 0 18
1 0 41984 56208 5896 353052 0 0 11 1279 1106 462 0 97 0 3
1 0 41984 56216 5904 353056 0 0 0 1256 1104 457 0 97 0 3
1 0 41984 56216 5904 353068 0 0 0 1282 1120 457 0 97 0 3
Nicholas
^ permalink raw reply [flat|nested] 2+ messages in thread
* RE: Large IO Waits for srm.
@ 2005-04-10 18:01 Ian Pratt
0 siblings, 0 replies; 2+ messages in thread
From: Ian Pratt @ 2005-04-10 18:01 UTC (permalink / raw)
To: Nicholas Lee, xen-devel
> nic@sea:/backup$ w
> 17:26:16 up 4:21, 1 user, load average: 1.00, 1.00, 0.92
> USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
> nic pts/1 base-one.kiwa.co 17:22 0.00s 0.01s 0.00s w
>
> The large IO wait level seems more than it should be. Here is
> an IDE based non Xen system doing the same.
I wouldn't necessarily trust the iowait time to be correctly accounted.
Does the srm delete take noticeably longer?
What happens if you do some simple tests to measure 'dd' performance in
both dom0 and the domU?
Best,
Ian
> nic@lode:/home/bak$ vmstat 3
> procs -----------memory---------- ---swap-- -----io----
> --system-- ----cpu----
> r b swpd free buff cache si so bi bo in
> cs us sy id wa
> 0 1 41984 57352 5856 352988 0 0 3 4 1
> 2 1 0 98 1
> 1 1 41984 56264 5880 353000 0 0 1 24937 2584
> 5174 1 29 0 69
> 1 0 41984 56264 5880 353020 0 0 0 6161 1417
> 1073 0 81 0 18
> 1 0 41984 56208 5896 353052 0 0 11 1279 1106
> 462 0 97 0 3
> 1 0 41984 56216 5904 353056 0 0 0 1256 1104
> 457 0 97 0 3
> 1 0 41984 56216 5904 353068 0 0 0 1282 1120
> 457 0 97 0 3
>
>
> Nicholas
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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