I had a question today around support for SMP-FT in an EMC VPLEX environment. It is well known that SMP-FT isn’t supported in a stretched VSAN environment, but what about other types of stretched storage? Is that a VSAN specific constraint? (Legacy) FT appears to be supported for VPLEX and other types of stretched storage?
SMP-FT is not supported in a vSphere Metro Storage Cluster environment either! This has not been qualified yet, I’ve requested the FT team to at least put it up on the roadmap and document max latency tolerated for these types of environments for SMP-FT just in case someone would want to use it in a campus situations for instance, despite the high bandwidth requirements for SMP-FT. Note that “legacy FT” can be used with vMSC environment, but not with VSAN. In order to use legacy FT (single vCPU) you will need to use an advanced VM setting: vm.uselegacyft. Make sure to set this setting when using FT in a stretched environment!
Bjorn says
Duncan, thanks for the post. I noticed that SIOC is also unsupported in a vMSC configuration. Any info on why this is and if there is a roadmap regarding this? Thanks.
Lex Luthor says
This. ↑
Duncan Epping says
http://www.yellow-bricks.com/2013/11/01/emc-vplex-storage-drs-storage-io-control/
Bjorn says
Duncan, thanks, I have indeed read the article. The question were more about the rationale, what makes SIOC not supportable in _any_ vMSC configuration?
We have a NetApp MetroCluster with NFS datastores, cannot see how or where SIOC would interfere? I also talked to a NetApp engineer regarding this, he said the same. From a NetApp perspective, the filer does nothing different with the (ESXi) host regardless of replicated or non-replicated disk.
If you can give any insight in this, it would be much appreciated. Many thanks /Björn
Duncan Epping says
That link explains it. Depending on the architecture implemented SIOC cannot see where the IO congestion is coming from. That is the reason engineering decided not to support it. When vMSC and VASA are more tightly integrated that should hopefully change
Bjorn says
OK, thank you for clarify. Looking forward for continued development of vMSC support.
arnaud ALAP says
hi Ducan SMP-FT there is a nother documentation which said SMP-FT is not supported vMSC in Vphere 6.
except this : Note that the new SMP-FT, introduced in vSphere 6.0 is not
supported on either vMSC or stretched cluster VSAN, but does
work on standard VSAN deployments. in this doc
http://www.vmware.com/files/pdf/products/vsan/VMware-Virtual-SAN-6.1-Stretched-Cluster-Guide.pdf
Duncan Epping says
Not sure I understand the question?
arnaud ALAP says
sorry , I just to know if the : SMP-FT still is not supported in a vSphere Metro Storage Cluster environment ?
Duncan Epping says
Correct, SMP-FT is still not supported over any type of stretched storage.