Re: rsync busy non-bare git repo 'source' to quiet

From: Neal Kreitzinger <nkreitzinger@gmail.com>
Date: Mar 8, 2011, 23:00 UTC
Message-ID: <4D76B52B.8070307@gmail.com>
In-Reply-To: <20110308223841.GA6648@sigill.intra.peff.net>

On 3/8/2011 4:38 PM, Jeff King wrote:

Show 22 quoted lines

> On Tue, Mar 08, 2011 at 04:20:33PM -0600, Neal Kreitzinger wrote:
>
>> Rsync seems like a simpler solution and more accurate solution for
>> creating a copy of an ecosystem of interrelated git repos colocated on
>> the same box.
>
> Sure. It is simpler, but not atomic unless you do a multi-stage rsync.
>
>> A previous post in the newsgroup states:
>>> If you want your rsync backup to be fine, you need to follow some
>>> ordering.  You need to copy the refs first (.git/packed-refs and
>>> .git/refs/), then the loose objects (.git/objects/??/*), and then all
>>> the rest.  If files are copied in a different order while some write
>>> operations are performed on the source repository then you may end up
>>> with an incoherent repository."
>>
>> Would that work?
>
> If you do it in that order, the end result will be a consistent repo.
> But during the copy, the refs at the destination will point to objects
> you don't have. I don't know if that matters for your case.
>

We won't be trying to used the "destination" repos during the rsync. The workflow will be: (1) I need to test a change to the goldbox change control menu system. (2) I determine that my testbox "copy" of the change control menu system has repos that are too out-of-date for a good test, so I run rsync to make a fresh copy of the goldbox. (3) After the rsync is finished, I pull over just the branch that contains my untested change menu scripts. (this is the only git pull i do from goldbox to testbox.) (4) I test the changes and see they are good. (5) I merge the changes into the master branch of the change control menu non-bare repo on the goldbox. The menu runs from the working tree so now they are live.

Since I won't be trying to access refs in the "destination" repos via git commandline or gui while the rsync is running, it sounds like it will be ok. I can keep people from banging on the testbox. I can't keep them from banging on the goldbox.

In regards to the working tree of a busy "source" repo, it sounds like it could end up not matching the index. At the end of the script I could execute a "git reset --hard && git clean -f" on each non-bare repo as you suggested. That would be pretty straightforward.

Thanks!

v/r, Neal