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Re: svnadmin hotcopy --incremental

From: Stefan Sperling <stsp_at_elego.de>
Date: Thu, 17 Feb 2011 12:11:06 +0100

On Thu, Feb 17, 2011 at 10:54:38AM +0000, Philip Martin wrote:
> Somebody responsible for backing up a large FSFS repository asked me if
> it were possible to do an incremental hotcopy. An incremental hotcopy
> would update a previous hotcopy to the current HEAD and would only need
> to copy the rev files newer than the previous hotcopy. This might
> involve deleting rev files if the packing has changed.
>
> Some strategy to deal with revprops would be needed: copy them all, read
> them all and copy the ones that have changed, copy the ones with newer
> timestamps, something else. The locks directory would need to be
> deleted and copied completely.
>
> Incremental hotcopy would start with a valid repository and end with a
> valid reposiory, but interrupting it part way through might result in an
> invalid repository.
>
> I don't think we can easily do this for BDB, so this would be an
> FSFS-only feature; since svnadmin already has BDB-only flags this should
> not be too much of a problem.
>
> Anyone see any problems with this approach? Does it sound like a good
> idea?

People are using rsync instead of hotcopy for this reason (and as long
'current' is copied first this is probably the best way of making incremental
backups).

So it would be great if we had a built-in way to support this.

It would be nice to come up with a solution that leaves the repository
in a well-defined state even if the operation is interrupted. rsync cannot
do that.
Received on 2011-02-17 12:11:49 CET

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