Change replica to thin disk?

[averylarry]

I think I can't but I'll ask. My replicas are currently thick and I'd like to change them to thin. Is there a method to convert them to thin that doesn't break the replication?

[Gostev]

The "proper" way to do this is specify different replica disk type per disk when creating the replication job. The job will then create replica disks as thin automatically for you. Any other method has not been tested. If I hear otherwise, I will update.

[robertson_scott]

Where do you set that (forcing the replica disk to thin) with Veeam 6? I can see the option under 5 (on the "Replica Destination" page) but there does not seem to be an equivilant for Veeam 6...

Ahh, I just found it under the "Pick Datastore" on the "Destination" tab for the job. But it looks like I need to set this individually for each VM in the job. My replication jobs each target a resource pool with around 12 VMs in each - I don't want to have to individually set this for each disk on each VM - am I forced to?

[foggy]

Scott, yes you need to set this manually for each VM, unless some of our PowerShell guys here know how to automate the process. Thanks.

[ThomasMc]

Scott, yes you need to set this manually for each VM, unless some of our PowerShell guys here know how to automate the process. Thanks.

I've had a good dig about the shell job options but can't seem to find what I need

[Sethbartlett]

Testing if I can force thick/thin on everything through powershell, will come back with some results here shortly.

[Sethbartlett]

I tried doing some force thick/force thin for "DiskCreationMode" in the ViReplicaTargetOptions in powershell but it still did "as source" as the GUI shows and ran a couple jobs. Still need to do some more research.

[averylarry]

I made it work. High probability of starting over from scratch if something doesn't quite work right. You've been warned.

1) Remove all snapshots on the replica vm.
2) Rename the virtual disk using vmkfstools -E replica.vmdk thickreplica.vmdk
3) Clone (and convert to thin) using vmkfstools -i thickreplica.vmdk replica.vmdk -d thin

When the next replication job runs, it'll recreate the metadata (calculate digests) and fail over to network mode (changed blocks information doesn't exist because it's a new virtual disk). But, for me, it did make the replica a thin disk without starting completely over (though I did lose all restore points).

6) After it's done and the replication job is working and it's thoroughly confirmed as working, you can delete the old virtual disk with vmkfstools -U thickreplica.vmdk

[Gostev]

Oh well, let's hope that the contents of your replica disks will still remain valid after the following incremental runs, since this scenario was never explicitly tested.

[averylarry]

I did a couple incrementals before posting. (Though I haven't actually tested a failover yet!)

Side note -- this might be a decent enhancement request . . .

[tsightler]

It just using the new disk as the seed, so it's really no different than "starting over" and using the exising VM, and it's newly converted thin disk, as the seed. Should work great.

[Gostev]

Yes, but if you noticed he maps thick disk into thin disk, this is what I am concerned with. Can never be too cautious with DR, I just want his replicas to work when he needs them

[averylarry]

Just tested the replica that I converted. It boots up and looks fine.

[tsightler]

Yes, but if you noticed he maps thick disk into thin disk, this is what I am concerned with. Can never be too cautious with DR, I just want his replicas to work when he needs them

Should be no problem. Mapping thick disk into thin disk is well tested by someone I know.