Backups are including white space, Is this Correct?

[sixth]

Hello!

I am currently testing Veeam Backup and I have one issue. When I backup a VM for example, that is 40GB, the backup size is approx 17.5GB, withh 88% compression ratio. Does Veeam also backup all the white space of a VM? The VM I am backing up is only using 8.5GB, but the backup is 17.5GB. If someone could provide some clarification that would be great! Thanks!

VM is residing on a ESXi host and I am backing up to a Windows File Share.

[Gostev]

Hello, did you have other VMs in this job before? Could you create new job with the same VM, run a backup and see the backup size? Theoretically, it should be smaller than 8.5GB.

[sixth]

Hi Gostev,

I did perform a backup previously, but this is a new backup job, not a template or anything. I will clear the job and recreate the job and try it again and see if its smaller than 8.5GB.

[sixth]

Does it matter that I am NOT using VCB and that this is an agentless backup since ESXi does NOT have a service console, would that effect the backup space being used?

[Gostev]

No, backup mode does not matter.

[sixth]

So I deleted the first job, and recreated and its STILL backing up the ENTIRE VM. I don't understand why, am I missing something?

0 of 1 VMs processed (0 failed, 0 warnings)

Total size of VMs to backup: 40.01 GB
Processed size: 4.00 GB
Avg. performance rate: 10 MB/s

Start time: 3/25/2009 7:28:01 PM
Time remaining: 01:02:05

[Gostev]

Sixth, I am not sure what you do you mean. We need to backup entire VM in order for you to be able to restore entire VM.
So what is the backup size for this new job?

[sixth]

Gostev,

Let me explain further. I just took a screen shot with that information above to show that its trying to back up the ENTIRE drive of 40GB. I canceled the job after this because the backup was already 12GB and it was only 34% done. My issue is its backing up the entire 40GB instead of only the 8.5GB that is being used by the VM.

VMDK in datastore is - 40GB
Space USED by the VM - 8.5GB

When I initiate the backup its backing up the entire 40GB. Is this correct? I thought we said it would only back up USED space of that 40GB?

[Gostev]

Sixth, do you have compression disabled in the backup job properties by any chance?

[sixth]

Gostev,

Nope. I do not have compression disabled. Would you like to see some screenshots?

[Gostev]

No need for screenshots, I trust your words

Then my next question is, are you sure the free disk space on your VM is really "white" (zeroed) like it is the case with newly created VMs, or this VM used to be filled by some files before which got deleted later? This would explain why backup file is bigger than actual used space (VMDK blocks are not really "white" but "dirty" so to say and cannot be removed by compression/deduplication). You can try to use the script referenced on the 2nd page of this topic (the script was created by one of our community members) and see if it helps.

[sixth]

I am going to try the script out and see if that helps. I will let you know! Thanks!

[sixth]

Ok i have tried the script. It has indeed helped, but its still not smaller than the actual Windows reported used space. The backup is now 9.5Gb, which is A LOT better than 17GB, but still larger than the 8 GB the vm is actually using, and considering this is compressed there is prolly still more Whitespace there. Any ideas what else I could do? I dont want to run this script on every machine.

[Gostev]

If you change compression in the job's setting to Best, you will get even better result. Default compression level is optimized for best performance and uses algorithm that consumes very little CPU cycles (since in case of network backup of fat ESX compression is done on the actual source ESX host).

As for script, consider it a maintenance activity similar to defragmentation on physical servers. Some people never defragment those and everything still works, just worse than in case of servers that have deframentation scheduled to run every couple of weeks.

Similarly, you may choose not to do wiping - the only thing it affects is your backup size and speed. But generally, zeroing virtual disks is a quite common recommendation in full image VM backup world.

[vbussiro]

If this is recommended, could you add in future release an option to wipe free space automatically before backing up ? Or maybe when the size of backup is too large regarding actual data used in VM filesystem ?

[Gostev]

Yes, I did log this potential feature based on original threads about wiping
We have one really really cool idea on how this can be done.

[sixth]

Gostev,

I changed the backup to use BEST compression. The backup is now 6.5GB, alot better. I also used the 'Shrink' virtual drive option under the VMware Tools options. This may have also helped. I hope you guys can get that 'cool' idea into a product update in the future, it would be GREAT!!

Thanks for the help!