[ZODB-Dev] Backing up Data.fs and blob directory

[Adam GROSZER]

Hello Laurence,

My only fear is that until today the preferred procedure to backup
ZODB was using repozo.py (if I don't miss there something).
It would allow doing backup while the app is online. And most of the
time we want to do that. Also incremental backups only when needed.

I guess repozo.py is not (yet) aware of BLOBs.
So the question would be, how to make backups with BLOBs?

Wednesday, September 3, 2008, 5:06:36 PM, you wrote:

LR> Backing up a ZODB has always been fairly easy in the past, but with the
LR> introduction of blobs things have got a little more complex.

LR> How should I create a consistent backup of my Data.fs and blob directory?

LR> My inital guess would be to take a copy of the Data.fs, then take a copy of
LR> the blob directory to ensure I have all blobs referenced in the Data.fs.
LR> Would I be able to restore from such a backup safely? (it may contain blobs
LR> from transactions that were newer than the backed up Data.fs).

LR> This should be safe because committed blobs are immutable and any dangling
LR> blobfiles would not interfere with the creation of blobs from new
LR> transactions in the restored zodb, as transaction ids would not overlap.

LR> I would be greatful if anyone could point out holes in my reasoning or has
LR> experience of this.

LR> Laurence


-- 
Best regards,
 Adam GROSZER                            mailto:agroszer at gmail.com
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