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Date: Fri, 26 Sep 1997 08:44:54 +0930
From: Greg Lehey <grog@lemis.com>
To: Terry Lambert <tlambert@primenet.com>
Cc: Mike Smith <mike@smith.net.au>, hackers@FreeBSD.ORG
Subject: Re: How do I check out a snapshot?
References: <199709251416.XAA04104@word.smith.net.au> <199709252147.OAA01744@usr04.primenet.com>
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In-Reply-To: <199709252147.OAA01744@usr04.primenet.com>; from Terry Lambert on Thu, Sep 25, 1997 at 09:47:44PM +0000
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On Thu, Sep 25, 1997 at 09:47:44PM +0000, Terry Lambert wrote:
>>> Sure.  But to repeat the question:
>>>
>>>    I see nothing in the tree to help me determine where, when or what
>>>    it is.
>>>
>>> How do I find it out?
>>
>> You don't.  Due to the nature of the distributed CVS repository, there
>> is a window where even the exact time of checkout for the snapshot
>> build might leave you out of sync.  The only way around this would be
>> for the snap to be built from a tree directly checked out from the
>> master repository.  Jordan does this for the for-CDROM versions, I
>> think.
>
> This is not due to the nature of the CVS repository; this is due to the
> way it is being used.  We've had the discussion about "how to use it
> to close the window" before.  Enforcing reader/writer locks by making
> the repository group writable and the locking program SGID the caller
> into the group would fix the problem, pronto.

This calls for something like the online snapshot capability of the
Veritas Volume Mangler.

More practically, wouldn't it be easy enough to defer updates on the
tree for an hour or two?

Greg