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Backup has SUCCEEDED with WARNING: Change Block Tracking could not be reset, causing full backup: Second attempt failed.

Hi,

Something strange here. Networker 9.1 with vProxy and only CBT backup, no NBD. All backups are succeeded. A few backups have the following warning: "Backup has SUCCEEDED with WARNING: Change Block Tracking could not be reset, causing full backup: Second attempt failed." This results in a longer backup windows because these vm's are fully backupped everytime.

The vm's have no other snapshots and virtual hardware is version 8 and newer. So incremental backup is supported?

Can't find the root cause. Someone any idea?

Cheers!

Vincent

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Re: Backup has SUCCEEDED with WARNING: Change Block Tracking could not be reset, causing full backup: Second attempt failed.

Hello.

Have you (or your VMware admin) tried to reset CBT for the affected VM?

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Re: Backup has SUCCEEDED with WARNING: Change Block Tracking could not be reset, causing full backup: Second attempt failed.

take a look at:

NVP-vProxy: Reseting Change Block Tracking

You need to reset the CBT of that VM, which is done at vCenter level.

This VMware KB explains the procedure to follow: https://kb.vmware.com/kb/2139574

To reset CBT on a vSphere virtual machine:
    1. Open the vSphere Web Client.
    2. Right-click the virtual machine and click Power Off.
    3. Right-click the virtual machine, click the Snapshot and navigate to Snapshot Manager. Ensure there are no active snapshots. If there are snapshots present, consolidate them to commit the changes. For more information, see Consolidating snapshots in vSphere 5.x/6.0 (2003638).
    4. Right-click the virtual machine and click Edit Settings.
    5. Click the Options tab, select the General section and then click Configuration Parameters. 
    6. Disable CBT for the virtual machine by setting the ctkEnabled value to false.
    7. Disable CBT for the individual virtual disks attached to the virtual machine by setting the scsix:x.ctkEnabled value for each attached virtual disk to false.
Where scsix:x is SCSI controller and SCSI device ID of your virtual disk.
    8. Open the virtual machine's working directory using the Datastore Browser or ESXi shell. For more information on identifying the working directory, see Locating virtual machine log files on an ESXi/ESX host (1007805).
    9. Ensure there are no snapshot files (.delta.vmdk) present in the virtual machine's working directory. For more information, see Determining if there are leftover delta files or snapshots that VMware vSphere or Infrastructure Client cannot detect (1005049).
    10. Delete any -CTK.VMDK files within the virtual machine's working directory.
    11. In the vSphere Web Client, right-click the virtual machine and click Power On.
    12. If you are using a backup application which utilizes CBT, you must re-enable CBT manually. Some backup tools automatically enable CBT, For more information, see Enabling or disabling Changed Block Tracking (CBT) on virtual machines (1031873).