Datastores and pre-allocation

[MrSpock]

Hi,

I have tried Veeam Backup for a few days now, and I just have to say: Great product! I have two (simple?) questions though:

1. I have VM's with disks on two different datastores. When I restore those VM's all disks are copied to the one datastore I choose as destination. I would like to choose a destination for each disk. Is that possible?

2. Are files pre-allocated during a restore operation? I've read that FastSCP does this to prevent fragmentation, but according to the datastore browser files are growing during the restore operation. Why is that?

Best regards,

Johan

[Gostev]

Hello Johan,

1. You can do this by selecting the second restore mode (Restore VM files), this allows you to restore different VMDK files to different datastores, however you will need to register the VM manually after this. We plan to add UI option for this scenario down the road too.

2. It should pre-allocate when restoring to ESX, but not to ESXi (because of different mechanisms used).

Thank you.

[MrSpock]

Gostev, thanks for your reply!

1. That's good!

2. Is that a limitation of ESXi or Veeam Backup? I am a bit concerned about the performance degradation that may occur due to fragmentation of the VMDK files during restore on ESXi.

[Gostev]

2. It could be both Veeam Backup "limitation" or "feature", or "ESXi limitation" - depending on what angle to look at it. When developing version 3.0, we have tested the restore mode that allows for disk preallocation, and found it slower than the other mode that we end up using. Anyway, VMware is adding new set of APIs with vSphere release (backward compatible with VI3), so we will be re-testing/re-considering the ESXi restore approach in the next release.

[MrSpock]

Gostev,

I am bumping an old thread here, so excuse me for that.

Does VRB 4.1 pre-allocate files on copy operations with ESXi 4.1 as target? I am evaluating this right now, but it seems that neither full VM restore or plain file copy does pre-allocate. Is that true?

[Gostev]

With ESXi, preallocation is only possible for thin disks, and in this case we do preallocate. For thick disks and any other files, it is simply not possible at the moment with VMware APIs.