Hi Lori,
Thanks alot for the feedback.
According to the logs, the wafl scan took ~1hr complete on an ~200GB system. Received a ratio of 1.02 :-)
My system is showing 10/15 seconds 100% spike in cpu usage when I'm mirroring data. Netapp figured it may be fragmentation on the disk. Their theory re fragmentation relates to the ratio of Disk kB/s read verus Net kB/s. From the sysstat output and perfstat data they indicate that I have a ratio of 3:1, where 1:1 should be the norm.
Has anyone else come accross this issue? I'm seeing it on systems running ONTAP 6.5.3P4 & 7.0.1R1.
From my research on the NOW site it appears to indicate that this is a known bug: http://now.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=140170
Netapp have asked me to review layer 2 flow control throughout my network and also to review the block size mount options.
Anyone out there running nfs with FreeBSD and seen any perfomance benefits of changing the block size? Our current block size is 8k.
Thanks, Philip
On Wednesday 08 March 2006 20:08, Lori Barfield wrote:
On 3/8/06, Philip Boyle philip.boyle@eircom.net wrote:
This may answer your question:
http://forums.netapp.com/searchresults.asp?pos=5&page=2&searchterm=w... n&searchact=ans&searchxid=0&searchcid=0
yum, thanks. :)
Lori, from your log snippet, I have a few questions which you might have some time free to reply on:
- Did the scan take ~1hr to run?
i wasn't watching sysstat, but the messages file wants us to believe it took 48 minutes during prime time.
- What size was the volume in question?
/vol/vol1/ 813694976KB 766782408KB 46912568KB 94% /vol/vol1/ /vol/vol1/.snapshot 25165824KB 23847548KB 1318276KB 95% /vol/vol1/.snapshot
(a flexvol.)
- Did you see any performance impact on the filer?
certainly not with the human eye. but we are overpowered and rarely run into user-detectable performance issues on the filer itself (even when i'm multithreading massive level 0 dumps from our sun server farm).
i didn't have a benchmark so i didn't bother with any kind of detailed measurements.
- Are you snapmirroring the volume in question? If so did you turn off
snapmirroring for the duration of the scan?
no snapmirroring.
...lori