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Replicating Citrix Netscaler VPX problem

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I am having a real issue replicating a Citrix Netscaler VPX Virtual Appliance.

The initial replication succeed fine but every subsequent replication fails with the error:

"Backup failed
Failed to enable Changed Block Tracking (CBT)."

Now, CBT is definitely turned off within the replication plan.

I can delete the replicated VM from the vSphere inventory and rename the folder in the datastore, run the replication again and it succeeds, run it a second time immediately after and it will fail with the CBT error.

I can delete the replicated VM from vSphere using 'delete from disk', run the replication again and it succeeds, run it a second time immediately after and it will fail with the CBT error.

So I look in my backup plan for this device and turn off / disable all CBT, Shadowcopy, Quiescing options just in case there is a link in there somewhere, but the behaviour remains.

Is there anyone out there that has one of these devices replicating normally.

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Hi,

You can also try to enable the CBT directly in the configuration file of the VM in question. Follow instructions outlined here https://kb.vmware.com/s/article/1031873 If still no joy, I'd recommend raising a support ticket for more in-depth investigation. 

Thank you, 

Hi - thanks for the reply, I've just checked the .VMX and the scsi0:0.ctkEnabled = "false" value isn't in there, so I might try powering it down and adding the line manually.

I have now resolved my issue, after experimenting with various combinations of ctkEnabled = "false" and scsi0:0.ctkEnabled = "false" in the VMX and nothing helping I decided to read up on CBT.

 

I found and read this page https://kb.vmware.com/s/article/1020128 and as soon as I saw "

  • The virtual machine owning the disks to be tracked must be hardware version 7 or later."

I checked the hardware version of my Citrix Netscaler VM and foud it to be hardware version 4 (!!) all my other VM's are a mix of hardware versions 7 & 8, so I upgraded the hardware version on the Netscaler to vmx-09 and now it replicates fine.

The replication API must be different from the backup API because backups were working fine all along.

Just putting this here in case it helps someone in the future.

 

frestogaslorastaswastavewroviwroclolacorashibushurutraciwrubrishabenichikucrijorejenufrilomuwrigaslowrikejawrachosleratiswurelaseriprouobrunoviswosuthitribrepakotritopislivadrauibretisetewrapenuwrapi
Posts: 250
Comments: 7092

Thank you for sharing your findings with the Community! Is definitely helpful