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slidek9
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Backup vs Replication

Post by slidek9 »

Hello,

I have recently learnt that when doing incremental backups, files that get deleted from the source servers do not get removed from the VBK file itself. I have tested this by removing 1.5TB of data (a disk exclusion) from a backup job and the size of the VBK file never got smaller (after selecting one rollback point to save and doing two backups).

Now I hear that to 'shrink' the VBK file you need to do a Full Backup (which is just a deletion of current data and a reset of the VBK?).

Veeam was brought by us to replicate a large amount of Data to the DR site across a slow link (37.5Mb); so we was going to Backup the servers and then from the DR site take a backup of the backup server.

But - now it looks like we need to take a weekly full backup to 'cleanup' the bloat in the VBK files - if we take a full backup at the main site, we would also need to take a full backup at the DR site; thus negating the whole 'Differential to the DR site' approach. Replicating the backup machine is out also because it does not use any compression and the CBT would get reset on a fullbackup.

So I am really struggling to see any benefit using Veeam for DR over DFS/Robocopy/ESX clones; hopefully I am missing something here - I really need some help with this please.

slidek9
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Re: Backup vs Replication

Post by slidek9 »

So, problem is:

Huge amount of fileserver data backed up locally; backup machine then replicated to DR site. So we have nice compression on the backup server and optimal replication using CBT. Sounds good.

Then, find out that Full backups still need to be done once a week of mostly static data, to avoid 'bloat' in VBK files (see above).

Now - we have not got enough bandwidth to do a new full replication each week to the DR site of 40TB of data no matter how it is compressed; we was pretty much sold on the ultra fast and efficient ' Synthetic Fulls ' as advertised. OC if we used Robocopy then it would just copy the changed files each and every time. Where am I going wrong with this planning for Veeam?

slidek9
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Re: Backup vs Replication

Post by slidek9 »

Can anyone help with this: Will VBK files shrink when source files are deleted from the fileservers disk?

(assuming a sdelete pass has been run)

Gostev
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Re: Backup vs Replication

Post by Gostev »

Deleting the data from NTFS volume does not change the actual content of disk blocks, and since we do image-level backup, this won't affect the VBK size.

Performing sdelete will change the content of disk blocks, so doing this will affect VBK, but VBK size will not be reduced (this is simply impossible without re-creating the actual file). Instead, blocks containing "old" data will be marked as unused, and will be available for reuse to store the new data. So when the new data comes in, it will be stored into those unused VBK blocks, instead of making the VBK file to grow in size.

I recommend to rsync your VBK to DR site, this should be most efficient in terms of traffic. This is what most of the customers prefer to do, based on the feedback. Please search this forum for "rsync" for more information on this.

slidek9
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Re: Backup vs Replication

Post by slidek9 »

Lovely Jubbly - Thank you Gostev

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