iSCSI does not support Cluster Shared Volumes (CSV) in Windows Failover Clustering

[NRForbes]

Hi,

I have been trying to use both FreeNAS 7 and FreeNAS 8 to provide iSCSI storage to a Windows Failover Cluster for use with Hyper-V. WFCS provides a special type of storage called Cluster Shared Volumes which enable Virtual machines to be move between cluster nodes "live". This requires that all nodes in the cluster can access the iSCSI volume simultaneously.

Unfortunately it apears that the iSCSI target used in FreeNAS does not fully support this.

Whilst the storage passes all the Cluster Validation tests and can be brought online once as a CSV, as soon as one node fails or you try to move the CSV to another node, the volume goes offline and cannot come back online. The only way to resolve the issue it to restart the iSCSI target.

The issue has been mentioned in the FreeNAS 7 forums:
http://sourceforge.net/apps/phpbb/freenas/viewtopic.php?f=53&t=8665
http://sourceforge.net/apps/phpbb/freenas/viewtopic.php?f=53&t=9367
which contain more details of the steps to re-create and the errors reported, however no-one has been able to suggest a fix up to this point :-(

I have also raised a bug report for this issue here:
http://support.freenas.org/ticket/322

If anyone from the FreeNAS 8 team is able to respond to this I would be happy to provide any additional information required or test new code/fixes?

Many thanks,

Nick.

 

[dstirrup]

Hi,

Did you ever receive a reply from someone knowledgable? I am looking for the same type of solution.

 

[Tekkie]

Is this not a limit of the istgt daemon rather than FreeNAS?

 

[survive]

Hi guys,

I think this is a limitation of the istgt software. As I understand it the program was updated in one of the 8.0.1 betas to resolve this problem, so if you can give Beta 4 a shot.

-Will

 

[JABFreak]

I am running Freenas 8.3.0 Release and I seem to be having the same issue as described by the OP.
I have 2 nodes and 10 VMs running, I can Live Migrate all VMs between nodes with no issues but if I attempt to change the CSV owner I loose the CSV for about an hour unless I restart iSCSI.
I have a fresh install, ZFSv28 pool / istgt (20111008)

 

[Pat]

I have the same issue, is there a fix for this? Unable to move CSV to another node

 

[JABFreak]

Makes me wonder why everyone wouldn't want to use Freenas with Hyper-V on CSV, it seems like a win win solution and why this has been left in the dark... mystery!
I guess people are going towards Openfiler but going the free way is complicated.

 

[jgreco]

I thought someone had found a workaround for this, but I am failing to find it. In any case, it does not work out of the box, and I believe that the problem was that istgt was selected because other target software options had different issues. It may be that FreeNAS is not the ideal choice for Hyper-V and CSV.

 

[ixdwhite]

I'm just curious what in iSCSI CSV requires for the switchover. iSCSI isn't a lot of magic.

I'll put this on my test list. I'll have to check if we have access to the appropriate licenses through our TechNet subscription.

 

[ixdwhite]

From a quick flip through the System Center 2012 - VMM docs, it seems to be expecting to have a SMI-S provider available so it can perform automated management operations on the storage (i.e., snapshot, create LUNs, rezone, etc.). FreeNAS doesn't have a SMI-S provider currently. Its possible the failover breaks because of the lack of said provider; the docs aren't clear that it is _required_ but the prereqs expect you to be using a storage system with such capability.

 

[Pat]

From a quick flip through the System Center 2012 - VMM docs, it seems to be expecting to have a SMI-S provider available so it can perform automated management operations on the storage (i.e., snapshot, create LUNs, rezone, etc.). FreeNAS doesn't have a SMI-S provider currently. Its possible the failover breaks because of the lack of said provider; the docs aren't clear that it is _required_ but the prereqs expect you to be using a storage system with such capability.

Is it possible there will be an update that will provide this kind of capability? Thanks

 

[dlavigne]

Please add a comment to the original ticket indicating that the fix did not resolve the issue.

I'll be glad when FreeBSD's in-kernel implementation of iSCSI is complete. It probably won't be available til 10 though.

 

[jgreco]

Please add a comment to the original ticket indicating that the fix did not resolve the issue.

I'll be glad when FreeBSD's in-kernel implementation of iSCSI is complete. It probably won't be available til 10 though.

They're putting an iSCSI target option in the kernel?

 

[dlavigne]

A complete in-kernel stack (target and initiator): http://freebsdfoundation.blogspot.com/2013/04/freebsd-foundation-announces-second.html.

 

[jgreco]

holy $#!+, totally awesome. I feel so old not even having any idea who that is though.

 

[dlavigne]

He did the grow live UFS/ZFS mounted filesystems work last year. We tried that on a Raspberry Pi at SouthEast LinuxFest and it "just worked" which was cool.

 

[paleoN]

LMAO, -103. Did you request that?

They're putting an iSCSI target option in the kernel?

Isn't there a FreeBSD news mailing list? I happened across the news on freebsd.org.

 

[dlavigne]

Isn't there a FreeBSD news mailing list? I happened across the news on freebsd.org.

Nope, but we'll be launching a FreeBSD Now! blog once I get a chance to finish setting it up and announcing it.

 

[paleoN]

Nope, but we'll be launching a FreeBSD Now! blog once I get a chance to finish setting it up and announcing it.

I was actually referring to FreeBSD-Announce, but I will take a look when it's up.

 

[jgreco]

I was actually referring to FreeBSD-Announce, but I will take a look when it's up.

It is pretty difficult to keep up on the mailing lists; I used to try (heck I used to be a frequent participant) but not so much reason to try anymore.