zoran4afc
Contributor
Contributor

Disappointing performance of Storage vMotion thin provisioned VM, iSCSI SAN, 10Gb LAN (Open-e DSS v7)

Hello,

My configuration is:

2 pcs. ESXi host installed at Supermicro MB X9DRH-7TF, 2x E5-2609v2, 64GB RAM, diskless

2 pcs. Open-e DSS v7 storage installed to Supermicro X9DRH-7TF, 2x E5-2609v2, 32GB RAM, 4x 4TB WD4000FYYZ in RAID5, built-in RAID performace read test: 472MB/s

The Supermicro X9DRH-7TF motherboard has onboard two 10GBase-T interfaces.

2 pcs. switch Netgear 8-port 10GBase-T ProSAFE Plus XS708E

Performing Storage vMotion from one storage to another of thin provisioned VM I am getting only 90MB/s data transfer rate (Esxi 5.5), compared to 1Gb LAN 40-65MB/s. Somewhat better I get with ESX5.1, 120MB/s over 10Gb LAN.

Thick provisioned VM performs much better, 280 MB/s (ESXi 5.5); 200MB/s (ESXi 5.1).

Further, the performance of ESXi 5.1 is 15% better with "iSCSI no delayed ACK". ESXi5.5 performs with "iSCSI no delayed ACK" the same as w/o, or slightly worse.

There is no performance improvement using iSCSI multipath round-robin compared to fixed path.

Confusing: Watching ESXTOP during Storage vMotion of thin provisioned I can see that the LAN Tx rate is double higher than Rx rate (Rx rate matches actual speed of Storage vMotion). Why is that? This is not the case with a thick provisioned VM; Tx and Rx speeds are the same.

Is that the best what I can expect from this configuration?

Is there a way to enhance Storage vMotion performance of thin provisionined VM, in light of confusing ESXTOP readings?

Thank you!

Zoran

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3 Replies
NealeC
Hot Shot
Hot Shot

This could be an issue with your Open-e DSS v7 not supporting VAAI yet.

It looks like it's still in testing with Open-E

http://forum.open-e.com/showthread.php?3975-Support-of-VAAI-for-Open-E-DSS-V7

Have you looked in the kernel logs etc. for any SCSI errors during the thin provisioned vmotion versus the log files during a thick disk vmotion?

Regards

Chris

-------------- If you found this or any other answer useful please consider the use of the Helpful or Correct buttons to award points. Chris Neale VCIX6-NV;vExpert2014-17;VCP6-NV;VCP5-DCV;VCP4;VCA-NV;VCA-DCV;VTSP2015;VTSP5;VTSP4 http://www.chrisneale.org http://www.twitter.com/mrcneale
zoran4afc
Contributor
Contributor

Thank you for the fast reply, Chris.

No errors in the vmkernel.log.

Regarding VAAI, I'll try generic Linux iSCSI and NFS, to compare with Open-e.

Zoran

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zoran4afc
Contributor
Contributor

Same speed with a generic Linux ISCSI SAN.

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