Keep in mind rsync is not erm, trivial to get going on Windows. On Thu, Sep 4, 2008 at 1:54 PM, Tres Seaver <[EMAIL PROTECTED]> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Christian Theune wrote: >> Hi Laurence, >> >> On Wed, 2008-09-03 at 08:06 -0700, Laurence Rowe wrote: >>> Backing up a ZODB has always been fairly easy in the past, but with the >>> introduction of blobs things have got a little more complex. >>> >>> How should I create a consistent backup of my Data.fs and blob directory? >>> >>> My inital guess would be to take a copy of the Data.fs, then take a copy of >>> the blob directory to ensure I have all blobs referenced in the Data.fs. >>> Would I be able to restore from such a backup safely? (it may contain blobs >>> from transactions that were newer than the backed up Data.fs). >>> >>> This should be safe because committed blobs are immutable and any dangling >>> blobfiles would not interfere with the creation of blobs from new >>> transactions in the restored zodb, as transaction ids would not overlap. >>> >>> I would be greatful if anyone could point out holes in my reasoning or has >>> experience of this. >> >> Snapshotting a blob directory after taking a copy of your Data.fs should >> be safe, as long as you don't pack in between. >> >> Note that at the design stage we imagined that blob directories might >> become really large making backups unfeasable. For those situations we >> handwaved a "very reliable storage" for this directory, like a >> self-contained SAN/NAS solution that keeps your data safe. > > Assuming we can avoid the race condition induced by packing during the > backup (see below), it should be possible to write a script which > combines of 'repozo' and 'rsync' in such a way as to get a "pure" copy > of the blob directory which corresponds to the repozo dataset. > Somethiing like: > > #!/bin/sh > touch .repozo_start > /path/to/repozo -B -f var/Data.fs -r backups/ > find /path/to/blobs ! -newer .repozo_start |\ > rsync -av --include-from=- /path/to/blobs/ backups/blobs/ > rm .repozo_start > > Packing *during* backup creates problems for repozo + blobs, because a > pack may cause "old" blob files to be unlined. Furthermore, it is not a > use case I think we should support. However, I don't think that > FileStorage supports the idea of a "pack lock" which would be acquirable > by repozo, so I don't know how to prevent the race. > > > > Tres. > - -- > =================================================================== > Tres Seaver +1 540-429-0999 [EMAIL PROTECTED] > Palladion Software "Excellence by Design" http://palladion.com > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.6 (GNU/Linux) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org > > iD8DBQFIwATJ+gerLs4ltQ4RAm0WAKC/jDUPqBnMTpwkDpBX0mKidGTxvwCghjnM > QYnz9dRolzOdvZX2t9fxM3k= > =/h4K > -----END PGP SIGNATURE----- > > _______________________________________________ > For more information about ZODB, see the ZODB Wiki: > http://www.zope.org/Wikis/ZODB/ > > ZODB-Dev mailing list - [email protected] > http://mail.zope.org/mailman/listinfo/zodb-dev >
-- Sidnei da Silva Enfold Systems http://enfoldsystems.com Fax +1 832 201 8856 Office +1 713 942 2377 Ext 214 _______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - [email protected] http://mail.zope.org/mailman/listinfo/zodb-dev
