Discussions specific to the VMware vSphere hypervisor
Post Reply
rct
Enthusiast
Posts: 35
Liked: 1 time
Joined: Sep 29, 2011 6:07 pm
Contact:

Help to understand why a so big backup file

Post by rct » Mar 10, 2015 9:05 am

Hello,

I had a filer VM which has been growing to a point where we couldn't handle the size of backup as we wanted.
We made some clean up to get to what we could handle but the backup was always the same size (because veeam doesn't know that files were erased).
I planned to create another vm disk where I rsynced the data but the backup was bigger... I don't understand why. Could you help me understand that ?

Some more informations:

Initial state
Filer VM with 4 disks stored in an iSCSI storage:
1. system (size 20GB)
2. data1 (size 2TB)
3. data2 (size 2TB)
4. data3 (size 500GB)
The full backup was 3.9TB

I have rsynced the content of the 3 data disks to another disk (5TB) stored in an NFS storage and configured the backup job to exclude disks 2, 3 and 4 from backup.
The full backup is now 6.11TB but the real data written into the disks is only 3.2TB.

My Backup job is configured as a synthetic full.

Any ideas to explain that?

Thank you.

veremin
Product Manager
Posts: 16908
Liked: 1440 times
Joined: Oct 26, 2012 3:28 pm
Full Name: Vladimir Eremin
Contact:

Re: Help to understand why a so big backup file

Post by veremin » Mar 10, 2015 9:38 am

The full backup is now 6.11TB but the real data written into the disks is only 3.2TB.
Can you elaborate on what full backup is meant? The full of the job you've excluded the disk from or the full backup of the newly-created job that has as its source VM to which you synced data?

rct
Enthusiast
Posts: 35
Liked: 1 time
Joined: Sep 29, 2011 6:07 pm
Contact:

Re: Help to understand why a so big backup file

Post by rct » Mar 10, 2015 9:44 am

The newly created disk is on the same VM so there is only one backup job.
The week 1 run of the job backuped all the 4 disks (system and data1/2/3).
The week 2 run of the job backuped 2 disks (system and the newly add 5TB disk that we will call data4).

foggy
Veeam Software
Posts: 18289
Liked: 1568 times
Joined: Jul 11, 2011 10:22 am
Full Name: Alexander Fogelson
Contact:

Re: Help to understand why a so big backup file

Post by foggy » Mar 10, 2015 10:52 am

You need to perform an active full to create a new VBK file and reclaim unused space. When some data is excluded from the job, backup file blocks are just marked as free and can be reused by new data, however the file itself cannot shrink in size (file systems do not support that). Active full creates a new backup file by grabbing only actual data from the original VM, so the resulting VBK will be much smaller - while old VBK will be removed by retention eventually.

rct
Enthusiast
Posts: 35
Liked: 1 time
Joined: Sep 29, 2011 6:07 pm
Contact:

Re: Help to understand why a so big backup file

Post by rct » Mar 10, 2015 1:44 pm

Ok thank you for your answer I will try to do that.

Post Reply

Who is online

Users browsing this forum: kapple, Senchoz, Vitaliy S. and 37 guests