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5 Posts
0
8358
Compellent SC420 and ESXI6
Hi,
We are using SC4020 as a iSCSI storage for our Virtual Environment with vSphere 6 for a while but now we are seeing issue of "Lost access to Volume..." throughout environment which brought me to question on VAAI and SC4202 compatibility with ESXi 6
Do Dell/Compellent recommended to have VAAI enable or disable?
Thanks
VirtObject
5 Posts
1
April 7th, 2017 09:00
I never contact Co-pilot support as I figured out from my own research.
It is known documented issue caused by VAAI ATS heartbeat and disabling it on hypervisor have resolve issue for me. You can look at detail on VMware KB at
kb.vmware.com/.../search.do
mtanen
118 Posts
0
September 16th, 2016 09:00
VAAI should be on...
We see this a lot when people dont do the fault-domain configuration properly. Simple test. Look at the iSCSI addresses on all of your controller iSCSI ports. If the IP addresses on those cards are in the same IP network - one fault domain.
Sometimes we see people put two fault domain definitions in - but it wont work if you are using the same IP subnet for all of the cards. (has to be on separate switching fabrics or different VLANs)
VirtObject
5 Posts
0
September 16th, 2016 10:00
Yup...we have single fault domain with all controller port are in same IP network.
I was looking at various VMware KB articles on this subject and general conscious on this subject is to disable VAAI on ESXi 5.5 U2 and later versions. We have started to see this error under heavy load causing I/O issues at VM layer.
Any other suggestion beside not disabling VAAI to troubleshoot this issue from Compellent SC4020 prospective?
rswislocki
52 Posts
0
September 22nd, 2016 01:00
Are SC recomended settings for VMware like: delayed ACK, PDL, queue depth and timeouts (OS, vm disk), settings for HBAs set properly?
Storage Center best practices (en.community.dell.com/.../20441056)
VirtObject
5 Posts
0
September 22nd, 2016 13:00
Yes.
We have followed best practices and adjust settings on Hypervisor and VM guests.
VirtObject
5 Posts
0
September 22nd, 2016 14:00
We are seeing flood of error messages in system manager logs
"Error IORPTracekey[xxxxxx] MZ[xxx xxx xxx] Sub[Virtualization] LUN[xx] [Write_xx] Cdb[xxxxxxxxxx}"
does that help to narrow down troubleshooting or getting in right direction to solve issue?
anhnh77
49 Posts
0
November 2nd, 2016 22:00
Hi,
You can engage Dell Copilot. It is very useful/supportive.
Regards,
RSwanson_VS
1 Message
0
April 7th, 2017 08:00
I am seeing the same errors. SCOS 7.1.4.4.
Did these errors ever get resolved? If so, what was the solution?
Thank you.