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Evacuating compressed data to non-compressed repository

Posted: Dec 12, 2017 9:43 pm
by DonZoomik
We have a few XFS repositories that store data with Veeam job compression. On the other hand we have ZFS/NTFS based dedup repositories that decompress data when writing it out to file system to achieve max dedup ratio from file system.
Options "Decompress backup data blocks before storing" on NTFS/ZFS and "Align backup file data blocks " on ZFS are set and are not set on XFS. Why do we use compression at all? To reduce network bandwidth (somewhat bottlenecked).

What happens when I evacuate data from XFS based repository (with compressed data) to repository that is supposed to have everything uncompressed? I presume that data should follow repository configuration and be uncompressed?

Re: Evacuating compressed data to non-compressed repository

Posted: Dec 13, 2017 11:26 am
by v.Eremin
How exactly do you plan to migrate the backup data between repositories? Thanks.

Re: Evacuating compressed data to non-compressed repository

Posted: Dec 13, 2017 12:34 pm
by DonZoomik
They're extents of the same SOBR.
1. Set XFS repository to maintenance mode
2. Evacuate.

Re: Evacuating compressed data to non-compressed repository

Posted: Dec 13, 2017 4:36 pm
by v.Eremin
Evacuation is a simple file copy operation, so the data will land on the second extent in compressed format. Thanks.

Re: Evacuating compressed data to non-compressed repository

Posted: Dec 13, 2017 11:22 pm
by DonZoomik
That explains why I'm not seeing expected dedup ratios. Thanks.

Re: Evacuating compressed data to non-compressed repository

Posted: Dec 14, 2017 11:50 am
by v.Eremin
Correct, so, you will have to wait till old compressed data ages out. Thanks.