[Zope-DB] Corrupt Data.fs

Matthew T. Kromer matt@zope.com
Tue, 06 Nov 2001 13:35:49 -0500

Hi Alastair,

You'll want to ask this of ZODB-Dev, not Zope-DB -- this list is for 
interactions with RDBMS systems.

Alastair Burt wrote:

>I posted two articles to the zope@zope.org mailing list[1] about this
>topic. Since I got only one oblique response, I am posting here to try to
>regain my faith in the ZODB. These are the problems that have seriously
>weakened my faith in the ZODB:
>  1. My Data.fs got corrupted and Zope would not restart. I have no idea
>     how this happend. Possible contributory causes might be no disk space
>     left or two Zope instances trying to serve the same Data.fs.
>  2. The fsrecover utility could not help me very much (nor
>     tranalyzer). They both bomb out. Tranalyzer tells me that there is a "
>     transaction lengths mismatch". Frustratingly, I can see actions in the
>     Data.fs (mostly changes to a Wiki) that tranalyzer fails to recognise
>     even when I give it a "-s" flag to start searching for transactions
>     after the problem with the transaction length.
>  3. One of the more worrying aspects of this corruption is that backups do
>     not seem to be much help to me. As far as I can tell, Zope was happily
>     serving requests for weeks from a database that it would not be able
>     to restart from. The backups made during this time are pretty much
>     unusable. I guess one way to counter this would be to kill and restart
>     Zope at regular intervals.
>Given these problems, can I trust the ZODB with valuable data again?