Advice on fully redundant Hyper-V cluster

[Olias]

There are a number of people (myself included) who are already doing this. You aren't in uncharted waters. iSCSI failover and SCSI-3 Persistent reservations has been in Open-E for a while.

Thanks for the reply. I know both features have been available, but I wasn't sure if anyone was actually using them for a redundant cluster shared volume in a Hyper-V environment. It's good to know I'm not the first...

[enealDC]

Np. And let us know how it goes. Sharing just helps evolve the product and helps new users.

[marcinrozanski]

You mentioned: "I've seen the documentation for using DSS in a Windows Server cluster, but not using TWO DSS storage servers to appear as a single, redundant storage device for the cluster."

That's true, one can find how to set 2 x Open-E in iSCSI failover and connect 1 x Hyper-V to it. And connecting multiple Hyper-V to Single Open-E is possible as well, BUT....

From the release notes:

“When using DSS V6 in windows 2008 cluster environment a failover event on DSS V6 will break i/o operation performed on the DSS V6 iSCSI target e.g. copying of files "

So it looks like Fully HA setup (everything x 2 ) is going to have some problems.

Apparently it's something that all storage vendors experience when dealing with Hyper-V.

I've seen guys running multiple ESX boxes off a single SAN box - failure !
SAN goes down , multiple ESX boxes loose access to the storage , 10s or 100s of VMs are down :-)

[enealDC]

Your mileage varies with whether or not I/O gets broken, but I've tested some settings for my customers that have overcome this issue for some workloads.
I've already posted some articles on this forum that aided me..h

[Olias]

I do have some concerns about what "DSS V6 will break i/o operation performed on the DSS V6 iSCSI target e.g. copying of files" really means in a real-world Hyper-V environmnet.

I hope to find out some time later this month. Right now I am waiting for a good time to move my current VMs off to a temporary third Hyper-V server while I build/test the cluster environment. During a catastrophic SAN failure, I could live with the VMs actually "crashing" and then restarting from the redundant SAN. 100% uptime is not a requirement for our environment; I'd just like to minimize any downtime.

I've already posted some articles on this forum that aided me..h

I'll do some forum searches and look at your tips!

[enealDC]

Well what it's trying to say is that when a failover occurs that there is a risk of IO operations being broken.
DSS isn't just breaking stuff randomly