Change block tracking

[gibsond4136]

If we did our initial replication of the VMs with them being VM version 4, does it have to do a full replication again if we upgrade them to VM version 7?

[Vitaliy S.]

Hello Dale,

You need to upgrade your VMs to hardware version 7 first and then perform another regular (non CBT enabled) incremental run to get a ChangeID for VMs. This ChangeID will be further used in incremental job runs.

Thanks!

[Gostev]

I am not 100% sure if CBT can be enable by incremental run... I think it might require full run... need to ask devs or QC.

[cby]

We had a bunch of VMs in a single backup job but one VM was not backed up with CBT. I found with an upgrade to VM 7 I had to set up a new backup job for that particular VM with the advanced configuration parameters on the VM itself set to 'ctkEnabled false' (on the VM and the relevant disks). When run with the same parameters using the existing backup job I get the following error for that one VM:

Verifying changed block tracking... Disk "Hard disk 2" has incorrect changed block tracking configuration. One or more VM disks have incorrect changed block tracking configuration. To resolve this, open VMware vSphere Client, right-click the VM, choose Edit Settings, Options tab, select General, click Configuration Parameters, and set all entries with ‘ctkEnabled’ substring to false. Veeam Backup will then automatically re-enable changed block tracking with the correct settings during the next job run.

Once I've run the new job ctkEnabled is automatically set to true in the configuration parameters on the VM. I can then go back and run the old job for all VMs and CBT is observed throughout.

Maybe the same principle applies to replication.

[Nikolaj7]

[merged into existing discussion]

Hi,

We have just bought and installed Veeam B+R 5.02.

We have several VM's both VM version 4 and 7.

VMware environment is vSphere 4.1.

There is a big file server at VM version 4 which takes long time to backup.

Next weekend we will upgrade it to VM version 7 so it can take advantage of Changed Block Tracking.

My question is, can we just do another normal scheduled backup after the upgrade which will enable CBT for this particular file server or do we need to initiate another new full backup of the file server virtual machine?

Thanks.

Regards,
Nikolaj7

[Nikolaj7]

Status is that we have backed up several VM's with version 4 and version 7 in the same Veeam backup job.

So will this procedure work:
1. Upgrade VMware Tools and VM hardware to version 7 according to VMware guidelines
2. Set ctkEnabled to false on each upgraded VM as per above post
3. Keep the upgraded VM's in the same Veeam backup job as before (CBT enabled)
4. Run the backup again and it will enable CBT on the VM's and backup the VM's than previously ran on VM version 4 virtual hardware

Thanks.

[Nikolaj7]

One follow up question:

In point 4 above should I run a full backup to get changeID's generated or does Veeam already have this registered for the VM version 4 machines?

[Vitaliy S.]

Nikolaj, ChangeID is only available for VMs with hardware version 7. As far as I remember CBT can be enabled with incremental backup job run too.

[Nikolaj7]

Thanks for your reply.

Any comments to the procedure I outlined above?
(I guess that it is not necessary to set ctkEnabled to false??)

Status is that we have backed up several VM's with version 4 and version 7 in the same Veeam backup job.

So will this procedure work:
1. Upgrade VMware Tools and VM hardware to version 7 according to VMware guidelines
2. Set ctkEnabled to false on each upgraded VM as per above post
3. Keep the upgraded VM's in the same Veeam backup job as before (CBT enabled)
4. Run the backup again and it will enable CBT on the VM's and backup the VM's than previously ran on VM version 4 virtual hardware

Thanks.

Do I risk to run into this error:

Verifying changed block tracking... Disk "Hard disk 2" has incorrect changed block tracking configuration. One or more VM disks have incorrect changed block tracking configuration. To resolve this, open VMware vSphere Client, right-click the VM, choose Edit Settings, Options tab, select General, click Configuration Parameters, and set all entries with ‘ctkEnabled’ substring to false. Veeam Backup will then automatically re-enable changed block tracking with the correct settings during the next job run.

Thanks.

[Vitaliy S.]

I'm not sure you should run into this problem because "ctkEnabled" should already be set to false after the upgrade.

[a.fokkema]

Check also the Independent mode configuration on the hard disk. This is also a show stopper for CBT. See my blog post for more information: http://ict-freak.nl/2011/06/24/disk-har ... iguration/