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Title
considerations and pre-requisites for VMware CBT (Changed Block Tracking) backups with Vmware plu -
Description
When VM machines are enabled for "Change Block Tracking" to allow Incremental block backups there are certain issues that may be encountered if this is not correctly set up.
There may also be a failure such as the following seen when backing up a VM with CBT enabled using the 2.1.80 plugin version:
Error 2012/05/21 09:16:01 1181 Data Plugin HRFBKPSERVER Failed to determine information for VM from the server
VMWVIM :02532 701 0 81601 Failed to get first set of properties: 4
VMWVIM :02532 214 0 81601 Failed to fetch props for a VM
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Resolution
The following configuration points need to be checked to allow the VM plugin to backup using 'Changed Block Tracking':
-Is the 'enable Changed Block Tracking' option enabled in the vmware plugin?
„-During the first Full Backup, run with the Enable Changed Block Tracking
for VM option selected, the target virtual machine must be powered off.
During the subsequent Full, Incremental or Differential backups, the virtual
machine can remain on.
„ -No snapshots must exist on a virtual machine at the time of enabling CBT on
it. For details, refer to http://kb.vmware.com/kb/1033816.
„ -The re-configuration of this parameter will take effect only after the virtual
machine goes through a stun/unstun cycle, including power on, resume after
suspend, migrate, or snapshot create/delete/revert
-Also for CBT the following priveleges need to be enabled for the vmware plugin user role (Adminisration->roles) in VSphere :
[edit] Backup involving CBT
Virtual Machine -> Configuration -> Disk change tracking (to enable CBT)
Virtual Machine -> Configuration -> Disk lease (san mode access)
Virtual Machine -> Provisioning -> Allow read-only disk access (to query for changed disk areas)
Virtual Machine -> Provisioning -> Allow virtual machine download (to read data from disk)
Virtual Machine -> State -> Create snapshot
Virtual Machine -> State -> Remove snapshot
Global -> CancelTask (if cancelling an action due to job abort. But this privilege is not required, atleast till ver 2.1 of the plugin, as none of the actions the plugin performs currently are allowed by vSphere to be cancelled.)
Global -> Licenses
Can you please try the following procedure as a potential workaround. If this does not resolve the problem then we will need to trace this I think which shouldn't be a problem as the job is only active for a couple of minutes before it fails.
Here first of all is the potential workaround of amending and resetting the vmx file for the image in question. Also did you verify the roles?
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In some cases we have seen the VMware CBT enabled backups fail with the following errors:
May see the VMware image backup fail with the following:
Error 2012/05/21 09:16:01 1181 Data Plugin HRFBKPSERVER Failed to determine information for VM from the server
VMWVIM :02532 701 0 81601 Failed to get first set of properties: 4
VMWVIM :02532 214 0 81601 Failed to fetch props for a VM
The Workaround for this is the following procedure:
Turn off the VM
a) Disable CBT
Edit the .vmx file of the virtual machine. Use vi or your favourite editor
Bfore editing it will look like this:
scsi0:0.ctkEnabled = "TRUE"
ctkEnabled = "TRUE"
After edting :
scsi0:0.ctkEnabled = "FALSE"
ctkEnabled = "FALSE
b) Stun/unstun cycle (Turn VM power on then off)
c) Enable CBT
Edit the .vmx file of the virtual machine. Use vi or your favourite editor
Before editing
scsi0:0.ctkEnabled = "FLASE
ctkEnabled = "FALSE
--- After edting ---
scsi0:0.ctkEnabled = "TRUE"
ctkEnabled = "TRUE"
d) Stun/unstun cycle b) Stun/unstun cycle (Turn VM power on then off)
e) Run the full backup job with CBT option selected (in the backup option).
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can you please check the following points regatrding the Changed Block Tracking enabled machine. You should be able to use this feature with the latest plugin version that you are using.
Is the 'enable Changed Block Tracking' option enabled in the vmware plugin?
„ During the first Full Backup, run with the Enable Changed Block Tracking
for VM option selected, the target virtual machine must be powered off.
During the subsequent Full, Incremental or Differential backups, the virtual
machine can remain on.
„ No snapshots must exist on a virtual machine at the time of enabling CBT on
it. For details, refer to http://kb.vmware.com/kb/1033816.
„ The re-configuration of this parameter will take effect only after the virtual
machine goes through a stun/unstun cycle, including power on, resume after
suspend, migrate, or snapshot create/delete/revert
Also for CBT the following priveleges need to be enabled for the vmware plugin user role (Adminisration->roles) in VSphere :
[edit] Backup involving CBT
Virtual Machine -> Configuration -> Disk change tracking (to enable CBT)
Virtual Machine -> Configuration -> Disk lease (san mode access)
Virtual Machine -> Provisioning -> Allow read-only disk access (to query for changed disk areas)
Virtual Machine -> Provisioning -> Allow virtual machine download (to read data from disk)
Virtual Machine -> State -> Create snapshot
Virtual Machine -> State -> Remove snapshot
Global -> CancelTask (if cancelling an action due to job abort. But this privilege is not required, atleast till ver 2.1 of the plugin, as none of the actions the plugin performs currently are allowed by vSphere to be cancelled.)
Global -> Licenses