ReadConflictError: database read conflict error (oid 000000000000bc8d,
The conflict error you have likely has nothing to do with your data loss, it's a normal artifact of Zope operation.
The first thing I would recommend trying today is shutting down, removing data.fs.index, and restarting. In recebnt versions data.fs.index make very heavy use of BTrees, and all released versions of the BTree code have small bugs.
Did you try this?
hm, isn't there a policy on adding tests that expose the bugs to the set of unittests ?
If you can replicate it, sure.
If we (our company that is)can't resolve the problem, we'll have to reconsider our strategy on data storage and perhaps even drop the use of the ZODB for anything but scripts and static content. all managed content types then have to stored in something more robust like some relational database, and we all know how well object trees fit into relational databases. :(
Yep. Fear, uncertainty, and doubt are sometimes more powerful than logic. ;-) - C