[ZODB-Dev] POSKeyError on startup

[Toby Dickenson]

On Thursday 02 October 2003 21:54, Paul Boots wrote:
> At 11:10 +0100 2-10-03, Eoin Curran wrote:

> >POSKeyError: 0000000000000006

oids are allocated sequentially, so your storage has lost the seventh object 
ever created! Thats quite distinctive. 

Have you run fsrefs to confirm that this is the only missing object? Or is 
this just the first one to get noticed out of a catastophic loss?

On a storage created today with zope 2.6.2, oid 6 is a TemporaryFolder 
instance. Is that a clue to anyone? its not to me.

This sort of damage can be fixed, but it needs surgery. You will need to 
confirm the type of the object that has been lost, then create a substitute 
object somewhere else in Zope. Next open the storage outside of Zope, use the 
storage API to load the pickle of the subsitute object, and store it as oid 
6.

> Oops - I'd say start again (with a backup plan).
> When you can't get to the object causing the error you're basicaly screwed.
>
> Does anyone no what sort of events trigger this error?
> I've had it and never got around the cause. It's a nasty and scary error
> that made me drop a level in trusting Zope.

If you need for your storage to absolutely never lose objects, then you may 
want to look at DirectoryStorage. I created it after getting the "you're 
basicaly screwed" feeling for the second time.

http://dirstorage.sourceforge.net/

-- 
Toby Dickenson