Host-based backup of Microsoft Hyper-V VMs.
Post Reply
GabesVirtualWorld
Expert
Posts: 244
Liked: 37 times
Joined: Jun 15, 2009 10:49 am
Full Name: Gabrie van Zanten
Contact:

HELP! Replica job changes disk format

Post by GabesVirtualWorld »

Hi
Replicating a Hyper-V (SCVMM) VM from a 2012R2 cluster to a 2016 cluster, also changes the harddisk type from fixed to dynamic. This is highly unwanted because when I need to change the disks back afterwards, it will take a lot of downtime.

How can I prevent this change in disktype? And why in heavens name, does it even happen?

Gabrie
DGrinev
Veteran
Posts: 1943
Liked: 247 times
Joined: Dec 01, 2016 3:49 pm
Full Name: Dmitry Grinev
Location: St.Petersburg
Contact:

Re: HELP! Replica job changes disk format

Post by DGrinev » 1 person likes this post

Hi Gabrie,

This behavior is expected and cannot be changed in the current version of the product.
We have it on the roadmap to change the said behavior in the future versions. Thanks!
foggy
Veeam Software
Posts: 21069
Liked: 2115 times
Joined: Jul 11, 2011 10:22 am
Full Name: Alexander Fogelson
Contact:

Re: HELP! Replica job changes disk format

Post by foggy »

Hi Gabrie, could you please tell why do you want to keep them fixed?
GabesVirtualWorld
Expert
Posts: 244
Liked: 37 times
Joined: Jun 15, 2009 10:49 am
Full Name: Gabrie van Zanten
Contact:

Re: HELP! Replica job changes disk format

Post by GabesVirtualWorld »

Hi,

The main reason we want to stay on fixed disks:
- We've discovered an UNMAP issue with our storage and dynamic disks on Hyper-V. Performance is heavily impacted when UNMAP is active.
- Our monitoring of the CSV volumes is currently based on fixed (and not growing) disks.
- For 1st line engineers it is quite a task to figure out if another VM can be added to a CSV when all VMs are thin.

Also a question for VEEAM: Why is the diskformat changed during a replication? Especially since it is nowhere to be found in the documentation that this change will happen and also the job creation wizard doesn't warn about this.

For the VMware Powershell cmd-let, there luckily is an option to force the disk type. But I also talked about this in the powershell section of the forum.

Can I use seeding to force the fixed format? Create first replica. Commit snapshot. Convert disk. Create new replication job and use the target as a seed?

Gabrie
foggy
Veeam Software
Posts: 21069
Liked: 2115 times
Joined: Jul 11, 2011 10:22 am
Full Name: Alexander Fogelson
Contact:

Re: HELP! Replica job changes disk format

Post by foggy »

Seeding might serve as a workaround, worth a try.
GabesVirtualWorld
Expert
Posts: 244
Liked: 37 times
Joined: Jun 15, 2009 10:49 am
Full Name: Gabrie van Zanten
Contact:

Re: HELP! Replica job changes disk format

Post by GabesVirtualWorld » 1 person likes this post

Nope, after making the first sync and committing the snapshot. I used that VEEAM as a seed and started a new replication. After the replication finished and removing the snapshot from the replica, I now have two VMs and both on dynamic disks. Quite a different behavior from VMware replication.
foggy
Veeam Software
Posts: 21069
Liked: 2115 times
Joined: Jul 11, 2011 10:22 am
Full Name: Alexander Fogelson
Contact:

Re: HELP! Replica job changes disk format

Post by foggy »

Do you mean the second VM was created when you mapped another job to replica with switched disk?
GabesVirtualWorld
Expert
Posts: 244
Liked: 37 times
Joined: Jun 15, 2009 10:49 am
Full Name: Gabrie van Zanten
Contact:

Re: HELP! Replica job changes disk format

Post by GabesVirtualWorld » 2 people like this post

I reran the test and I think I messed up in the first test. The second time it worked as expected.

Original- VM (fixed disks) --> Replication to ReplVM
ReplVM is dynamic with differencing disk (Snapshot).
Remove Replica Job.
Commit snapshot on ReplVM.
Convert ReplVM to fixed disk.

Then create new replication job to create replica from Original-VM to new VM and use ReplVM (with fixed disk) as replica (seed).

End result:
Original-VM = fixed
ReplVM = fixed with snapshots. Strangely enough the ReplVM was not renamed to the new suffix in the job, but kept the name of the mapped VM.
I then performed the final failover and I now have a running replicated VM with fixed disk.

Sadly though I do have some extra work with converting and then re-seeding, but for now it is a workable alternative.
migmol55
Certified Trainer
Posts: 1
Liked: never
Joined: Jan 04, 2017 12:16 am
Full Name: Miguel Molina
Location: Sao Paulo - Brazil
Contact:

[MERGED] Replica Hyper-V ==> Dynamic Disks

Post by migmol55 »

Hi

When I configure a VM in Hyper-v for replication VEEAM VBR v10 change the disk format for Dynamic Disks.

Is it possible VEEAM in replication doing the Failover / Planed Failver action maintain disk format as FIXED Disks?

Is there any advanced configuration in VEEAM Backup and Replication v10 to maintain disks format?

Thank You.
Regards.

[]s MM
Egor Yakovlev
Veeam Software
Posts: 2536
Liked: 680 times
Joined: Jun 14, 2013 9:30 am
Full Name: Egor Yakovlev
Location: Prague, Czech Republic
Contact:

Re: HELP! Replica job changes disk format

Post by Egor Yakovlev »

Hi Miguel,
I have merged your post to the existing thread.
This is expected behavior and workaround above with seeding should be valid still.
/Cheers!
Post Reply

Who is online

Users browsing this forum: No registered users and 28 guests