Re: Data duplication when moving datafiles from one server to another.

IñigoMartinez Lasala <imartinez@vectorsf.com> wrote:

> Yesterday we experienced some data duplication in several database
> tables after one sysadmin decided to test in a production
> environment an rsync script in order to migrate a database from
> one server to another one.
> Postgresql (8.2) was running in source server and rsync script was
> launched from second one. Second one server had a one day old copy
> of the same database. Rsync script create a datafile replica in
> destination server.
> Our sysadmin swear he didn't launch the script in a reverse way
> (that is, from destination to source)... so my question is
> How this data duplication could happen?

Where did this duplication happen -- source or destination?  If in
the source, I would suspect operator error by your sysadmin; I have
never seen rsync cause problems with the source files.  If on the
target, I would suspect that you didn't follow PITR recovery
techniques properly.

If you need to follow up on this, please include a few more details,
like the exact PostgreSQL version from `select version();` and the
exact version of the OS.  The exact rsync statement(s) used would be
good to see, too -- maybe from the bash history (or similar) on the
machines.

-Kevin