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4587
January 30th, 2014 03:00
Disabling CBT on VM, impact on Avamar backups ?
I am backing up my Cloud environment with Avamar and to fix a issue with vCloud Director, I need to disable CBT on the VM. What impact will it have on my Avamar backups ?
Resolution
To work around this issue, disable CBT on the virtual machine.
Caution: Disabling CBT may cause issues with your backup software as most solutions require CBT for optimal performance. Engage your backup solution vendor for any implications on disabling.
Does Avamar uses the CBT in the VM or its own CBT to backup using de-duplication method ?
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FabEdf
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42 Posts
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March 7th, 2014 01:00
You can disable CBT you will get Avamar dedupe, but speed of reading will be less good than it has to be with CBT.
Try it just on one VM, you will see the difference.
CBT is set up by VM and not on whole ESX or vCenter.
Hope I am clear.
Regards,
F@b
FabEdf
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42 Posts
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March 3rd, 2014 08:00
Hi,
Avamar use CBT from VMware, I don't think that any backup software provide it's own CBT.
The impact will be on the backup speed, you will take a snapshot of your VM and backup it on a full way.
HTH,
F@b
pawankumawat
355 Posts
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March 4th, 2014 01:00
Hello,
If CBT is selected, the VMware changed block tracking feature is used to identify areas of the virtual machine file system that have changed since the last backup and only process those changed areas during the next backup.
Changed block tracking must be enabled at the virtual machine level in order for this feature to work.
Regards,
Pawan
avinashpattnaik
6 Posts
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March 6th, 2014 02:00
Hi,
Thanks for your inputs. Doesnt avamar uses its own de-dup feature ? If the data is already presented on Avamar server, it wont back it up ? Since we have issue with VCD , we have to disable CBT on our VMs. I dont want all my backups to be full backups now.
FabEdf
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42 Posts
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March 7th, 2014 01:00
Keep us informed please.
F@b
avinashpattnaik
6 Posts
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March 7th, 2014 01:00
Hi f@brice,
Thanks for the details. Could you please tell me if I diable CBT on my VMs, Avamar can still perform de-dup backups ?
I want all my backups to be de-duped in Avamar even if CBT is disabled rather than backing up already backed up data again.
FabEdf
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42 Posts
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March 7th, 2014 01:00
Hi,
CBT and Dedupe from Avamar are not the same thing.
CBT is a log for blocks which are changed since the last snapshot, and has nothing to do with dedupe, this feature is use to accelerate speed disks reading.
Avamar's dedupe is to cut, compress and compare chunks to send less data as possible on the network.
Regards,
F@b
avinashpattnaik
6 Posts
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March 7th, 2014 01:00
Thanks f@brice, much appreciated.