CTK.VMDK files get created automatically

[SDquality]

We have a VM called ISTQB, yesterday morning it was noticed that this was offline. On investigation we found that the VM had a 'consolidation needed' message. I performed the consolidation which failed. On investigation of the Datastore within which the VM resided we found CTK.VMDK files for each of the HDDs. After doing some research I removed the CTK.VMDK files and managed to power up the VM. We would now like to find out how this happened?. The problems seemed to begin at around 07:06 on 25/06/2014.

Can anyone explain or share your views on this.

[a_p_]

The .-ctk.vmdk files are used for CBT (Changed Block Tracking). Unless done manually, CBT is usually enabled by backup applications. What do you use for backup?

André

[SDquality]

Andre, thank you for the reply.

The backup software is veeam Backup & Replication Version 7.0

I need to know why the ctk.vmdk files failed to be removed and in turn halted the VM in my environment.

Thanks again!

[a_p_]

Once created, the CTK files are not removed anymore, because they are contain the information about the virtual disk's (.vmdk files) changed blocks, which the backup software needs to optimize incremental and differential backups.

I don't think that the CTK file itself caused the issue (keeping track of changed blocks is implemented in the Hypervisor, i.e. not the backup software). Maybe the VM's vmware.log files contain some hints on what happened!?

André.

[NavalgundRaj]

Hi SDquality,

As I already gone through this chain of reply on this and came to know there is backup software which is causing the .ctk files to not to get deleted.

Go to veeam backup virtual machine and you can see the vm machine ( eidt settings of the backup VM) disk still hanging there which is showing .ctk file that is failed to consolidation.

and release from the veeam Vm and then you consolidate it and it will successfully consolidate.

not need to remove the .ctk file.

OR please share how you got resolved.

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Regards

Basavaraj.R Navalgund

[SDquality]

Hi Andre,

Hope you are doing great.

Do ctk files get removed after Snapshot consolidation automatically or do we need to manually remove them?

[a_p_ · Accepted solution]

A separate .ctk file is created for each virtual disk (.vmdk) file, i.e. for base disks as well as snapshots. Once a snapshot is removed, its associated .ctk file is also removed. However the base/parent virtual disk's .ctk file gets updated, and will NOT be deleted, which is the expected/wanted behavior

I'd suggest you don't delete .ctk files manually, unless you are instructed by e.g. VMware Support to do so!

André