Advice on fully redundant Hyper-V cluster

[enealDC]

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.

[jtucker]

I am also setting up failover with VMware - 2 open-e boxes (6 nic's each) and two vmware boxes (6 nic's each) with two storage switches. Is broadcast or unicast better? Is one more resiliant to switch failure or quicker to detect failure?

[To-M]

Using broadcast is best used with small amount of systems on the network where unicast is best used with many servers so the management packets will be unicasted between specified the IP addresses.

[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