On Tue, Dec 13, 2016 at 4:17 PM, Andrew Martin <amartin_at_xes-inc.com> wrote:
> Hello,
>
> I am running a Subversion 1.9.3 server on Ubuntu 16.04. I currently use
> svnadmin hotcopy to safely backup the SVN repositories, but since the
> repositories are now hosted on a ZFS dataset, I would like to utilize ZFS's
> snapshot capabilities to create atomic, point-in-time backups of the
> repositories. My plan to do this is as follows:
>
> 1. create zfs snapshot
> 2. clone zfs snapshot and mount at a temporary location
> 3. run svnadmin hotcopy from the mounted clone to safely create a backup
> 4. umount and destroy clone
>
> My only concern is if a commit is in-progress when the zfs snapshot occurs,
> would svnadmin hotcopy still be able to safely handle creating the backup?
>
svnadmin hotcopy will not have a problem with an in-process commit. That
is kind of one of the points of that command.
> Is this a safe procedure for creating backups?
>
I know very little about ZFS but I do not understand why you would do
this. If it can take snapshots, then why wouldn't you just take a snapshot
of the actual live repository, why would you want to copy it?
Setting that aside, I think hotcopy is a very good way to do backups ...
but it is not clear what value would come from taking a snapshot of the
backup given that version control history is immutable etc. Also, once you
create the initial hotcopy, you can use the hotcopy --incremental option to
just copy the newer revisions. Do that from a post-commit hook and you can
always have a backup up to the latest commit.
To me snapshots would seem like a way to do backups without using hotcopy.
I am not sure the value of combining the two ... but it should work
technically if you have "reasons".
Mark
Received on 2016-12-13 22:35:40 CET