[Zope-dev] Weird Data.fs corruption...

[Jim Fulton]

Carl Robitaille wrote:
> 
> Hi everybody,
> 
>         I looked around the Zope site and mailing lists, but I wasn't able to
> find an answer to my problem.

That's because your problem only existed for a few hours. Sigh.

> I'm using the CVS version of Zope2.

We try to keep this stable, but no guarantees.  Some changes were
checked into CVS on Monday night that caused the problem you observed.

> I did
> an update yesterday.

Unlucky you. :/

> Since then, there's been some commits.
 
(snip)

Copy/paste (export/import) were broken and led to database corruption.
I checked in the fix to this yesterday.

> 
>         I then logged to Zope web site to get information on how to get my
> Data.fs fixed. I read the
> http://www.zope.org/Members/itamar/CorruptedZODB document and downloaded
> the tranalyzer.py python program. I then understood what the backtrace
> already told me. The first 4 bytes of any ZODB files should be something
> like "FS21". Instead, I have garbage in my Data.fs:

Right. The bug caused the file pointer to get incorrectly set at 0, so
transactions after the copy/paste errors were written at the beginning 
of the file.
 
> [zope@petechie var]$ python tranalyzer.py Data.fs | more
> Traceback (innermost last):
> error: Not a .fs file (at least, not a kind I know about)
> magic =
> 6TĘ
> 
>         Just for the record, Data.fs.in is read easily by tranalyzer.py.
> 
>         How can this happen? Any idea?

I think I answered that.

> My only "guess" is that it has to do
> with the Data.fs file being used by ZServer over an NFS partition on
> Linux. This is only a guess, but I really can't see any other thing I
> could have done wrong.

It was a software bug, which has been fixed.
 
>         This doesn't really bug me for the moment as I only had a couple of
> hours put in my site, but I would like to prevent it from happening
> again.... yes I do backups, but only once a day ;-)

It shouldn't happen again.
 
Jim

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