[svn.haxx.se] · SVN Dev · SVN Users · SVN Org · TSVN Dev · TSVN Users · Subclipse Dev · Subclipse Users · this month's index

Re: Repo packing with subversion 1.6 results

From: Hyrum K. Wright <hyrum_wright_at_mail.utexas.edu>
Date: Fri, 27 Mar 2009 08:16:54 -0500

On Mar 27, 2009, at 12:54 AM, B Smith-Mannschott wrote:

> On Fri, Mar 27, 2009 at 02:45, svnuser <jzaniewski_at_gmail.com> wrote:
>> I have sharded repo using 1.5.6 with 22K revisions, size 2.9G
>> I loaded its dumps into a new repo using 1.5.1 (I meant to use
>> 1.5.6 but
>> this should do)
>> My new repo has the same size as my original (expected).
>> I run upgrade/packing on it with 1.6 and all I save is 100M.
>> I load the dumps again but this time I use 1.6 and my repo is now
>> 2G. I do
>> the packing and my repo shrinks by 100M.
>> Are these expected results?
> Yes

Depending on the size of the revisions (the amount of "stuff" in them)
and the underlying OS filesystem, packing will have varying amounts of
benefit. Generally, the space savings will be proportional to the
number of versions in the repository.

>> Why such diff in size loading with 1.6?
>> btw my repo is mostly source code but I do have some binaries.
> <http://subversion.tigris.org/svn_1.6_releasenotes.html#filesystem-improvements
> >
> # Sharing multiple common representations (issue 2286, server)
> # ------------------------------------------------------------
> #
> # When using many branches and merging between them often, it is
> common
> # to have files with similar lines of history which contain the exact
> # same content. In the past, Subversion has stored these files as
> deltas
> # against previous versions of the file. Subversion 1.6 will now use
> # existing representations in the filesystem for duplicate
> # storage. Depending on the size of the repository, and the degree of
> # branching and merging, this can cause an up to 20% space reduction
> for
> # Berkeley DB repositories and a 15% reduction for FSFS repositories.
> ------------------------------------------------------
> http://subversion.tigris.org/ds/viewMessage.do?dsForumId=1065&dsMessageId=1440247

The major decreases you are seeing are from rep-sharing, as noted
above. For rep-sharing to work, the rep-cache has to be populated,
which happens when you load the dumpfile on the 1.6 repository. Doing
an 'svnadmin upgrade' to 1.6-format will enable rep-sharing going
forward, but it does not populate the cache with existing revisions,
nor rewrite old history to use rep-sharing.



To unsubscribe from this discussion, e-mail: [users-unsubscribe_at_subversion.tigris.org].
Received on 2009-03-27 14:18:11 CET

This is an archived mail posted to the Subversion Users mailing list.

This site is subject to the Apache Privacy Policy and the Apache Public Forum Archive Policy.