Backing up a Windows Failover Cluster with Shared vhdx?

[spgsit5upport]

How do I go about backing up VM Guest Failover Cluster with shared vhdx?

Obviously same vhdx is assigned to two (or more) cluster members.

I do not want to have them backed up x-number of times

Seb

[Vitaliy S.]

Hi Seb,

Shared VHDX virtual disks cannot be backed up, as Microsoft does not currently support host-level backup of these disks.

Thanks!

[spgsit5upport]

But that is madness! I have FOC which can not be backed up!

I do not want agents inside VM!

Now I need to ditch the cluster idea to get the backup going.

Seb

[Gostev]

But that is madness! I have FOC which can not be backed up!

You are not alone, being Hyper-V MVP I can tell you that many Hyper-V users are screaming the same words at Microsoft, because lack of backup means the actual feature is plain useless. So, I am sure this omission is a priority for Microsoft to address. To be fair though, this approach is not a unique situation in the industry - for example, VMware released Fault Tolerant VMs many years ago, and these VMs still cannot be backed up with VADP today.

The good news is that we managed to add crash-consistent Shared VHDX backup to B&R v8, and I think we can all agree that crash-consistent backup is infinitely better than no backup at all

[spgsit5upport]

So I can upgrade to 8 (maintenance comes handy) and have a backup of shared vhdxs? Sure, crash consistent is way better then none!

Seb

[Vitaliy S.]

Yes, that's correct.

[spgsit5upport]

But that is yet some way off, right?

Seb

[veremin]

According to the plan, v8 should be released in late Q3, 2014. Thanks.

[Vitaliy S.]

You can also subscribe to this page in order to be notified about its availability > http://go.veeam.com/availability-suite-v8

[RGijsen]

Sorry to resurrect this rather old thread, but I think there have been more than enough threads about this so donn't want to open yet another one. I've been struggeling to 'sell' Veeam to myself being the decision maker on that. We have clustered fileservers, Exchange and SQL. While SQL and Exchange have some alternatives like mirroring and DAGs (at the cost of alot of storage) DFS is not really an alternative for us for the fileservers.

While Hyper-V does not support snapshotting shared disks, I wonder why it isn't possible to use the offhost proxy to mount the storage directly on the SAN. As hardware snapshots are used there it doesn't make a difference even if the VHDX was shared or not. When used together with quiesce / VSS inside the guest to properly 'stall' the FS I don't understand why even Veeam V8 will only support crash-consistent. I must be overlooking something evident here but I just don't get it.

[Vitaliy S.]

Hello,

I wonder why it isn't possible to use the offhost proxy to mount the storage directly on the SAN.

To the best of my knowledge Microsoft does not have any ways to create a VSS snapshot of the volume with shared vhdx files in-place.

When used together with quiesce / VSS inside the guest to properly 'stall' the FS I don't understand why even Veeam V8 will only support crash-consistent.

As far as I know there is no way to create a in-guest VSS snapshot of shared VHDX, that is why only crash-consistent backup is possible.

Thank you!

[RGijsen]

Hi,
yes its true MS doesn't support VSS snapshots on host-level. However, it's absolutely possible to create in-guest VSS of the filesystem with shared VHDX. We have used in-guest snapshots for years on our fileserver-cluster. Several months ago we moved that from physical machines to Hyper-V guests with virtual HBA's. Still with VSS enabled and working fine. I recently moved the SAN LUN's to shared VHDX files, to prepare for V8's somehow-ability to backup them. VSS however still works and is perfectly supported - wouldn't make sense to have a file-cluster that doens't support VSS; inaddition, in-guest VSS ofcourse stays inside the vhdx file - or on the clustered disk in this instance.

To prove my 'theory' what I did is the following:
on a testcluster I created a few in-guest snapshots of a clustered fileshare-disk that's a shared vhdx. I can make snapshots inside the guest just fine:


Creating snapshots on hyper-v host level is not possible. Creating a snapshot on the storage though (which could be done on a OffHost proxy) is ofcourse possible. The VHDX in that snapshot is not consistent ofcourse, but the in-guest snapshot inside that VHDX is. I mapped the storage snapshot to a machine here and can access that just fine after assigning it a driveletter for convenience. The Veeam_cluster_test.vhdx is the actual shared vhdx:


Then I copied the VHDX file to a local disk. Powershell doesn't seem to support mounting a VHDX on write-protected media, even if I supply the -readonly switch. That's not an issue for Veaam though, as the off-site proxy has read-only access to the snapshots anyway and can access the file.
Mounting the image file and listing the snapshots inside that vhdx:


Then using a regular cmd prompt I use mklink to mount that snapshot and presto; I can access all snapshots in the VHDX like that, and could if I want even easily move between snapshots in that vhdx:



So while this is a very awkward way of doing things, it DOES show I can have consistent data INSIDE a vhdx using in-guest VSS and after that snapshots on the storage box. The VM does not have to power down, in fact it kept running while I made this test for this post. While I know my approach here is more on file level than on block-level, I would kill to see Veaam support backing up cluster disks - even if through file level. Clusters are not passé, in fact I really advocate the use of them to save on storage (DAG / mirrors / DFS all require storage * numbers of hosts) which is expensive for small companies like we are. However, you guys probably have insane knowledge of working on blocklevel, so maybe you can even extract whatever you need in block-level from the VHDX.

I have this test setup available at any time, might you want to see this just contact me. Glad to help if I can.

[spgsit5upport]

So does V8 support backup of shared vhdx OOB without anything else needed?

Just select them & go?

Seb

[foggy]

Yes, shared VHDX can now be backed up in a crash-consistent state.

[spgsit5upport]

So indeed that is the case. Nice, thanks.

Does it matter which node is selected for the backup? (in my test I used the node that did NOT owe the disks at the time, but the backup happened anyway, apart from one drive not presenting letter during restore process)

Seb

[foggy]

No, this should not matter.

[Vitaliy S.]

I have this test setup available at any time, might you want to see this just contact me. Glad to help if I can.

Great post and good knowledge of how everything works in Hyper-V. Sorry for the late reply.

What you have just done is basically what Hyper-V VSS writer does when backing up VMs on the host. Unfortunately, this writer is not currently capable of doing the same VSS freeze for shared VHDX, which we are using for backing up Hyper-V VMs.

[spgsit5upport]

No, this should not matter.

But how to backup the send VM of the cluster?

Will the shared disk be tried to be backed up ONE MORE TIME?

If I select Exclusions & System Disk Only, I get Size of the VM as 0.0 Kb, only way to get it was to select disk/SCSI & then chose the disks I need for this VM

Seb

[foggy]

It will be backed up twice, if nodes are backed up by different jobs. If they are in a single job, the disk will be snapshotted twice (within each node), however backed up with the first node only. The second node backup will contain differences for this disk between the snapshots.

[Someonenew2014]

Hi...

We are using shared VHDX and would like to take backup in application consistent-state. We know it is not supported.

We are looking for options/ideas to make it work with Veeam.


Appreciate your cooperation in this matter.

[mdallagi]

Hi, here the same problem

and today the Veeam support also confirmed to me that the v9 doesn't yest support this.
any forecast for this functionality?

Thanks.
Max.

[Someonenew2014]

We know it will not be suppoertrd and it is a Microsoft thing. It is a limitation.

We are looking for workaround from Veeam, some vendors provide Agent for such a case.

I'm sure Veeam can find workaround for this issue.

[Vitaliy S.]

Massimo, cannot make any forecasts on availability of this functionality, let's see what improvements a new version of Hyper-V will bring. Most VM image-level backup vendors cannot do backups of these VMs at all. One of the possible solutions would be, indeed, to run an in-guest script/agent to initiate VSS freeze during a VM-level backup job, though it would bring more complexity into overall backup job management.

[Someonenew2014]

Hi,

I saw many posts talking about Hyper-v 2016 new features (Shared vhdx).Windows Server 2016 many of these limitations have been removed and key features with shared VHDX now include:

Dynamic resize (resizing while VMs are running)
Host level backup
Hyper-V Replica support


http://windowsitpro.com/windows-server- ... erver-2016


How this sounds ???

[foggy]

Promising. However nothing specific at the moment, we have yet to take a look at it.

[Andreas Neufert]

Do our Change Block Tracking work with these shared VHDX disks or is it Snap and Scan Backup?

[Vitaliy S.]

Yes, it does work as with regular disks.

[Andreas Neufert]

Cool Thx

[Andreas Neufert]

I´m sorry ... follow up question by a customer.... will Indexing work for 1-Click File Restore ?

[Vitaliy S.]

Yes, that would be possible too.