On 7/28/06, Arnaud Lesauvage <thewild@freesurf.fr> wrote:
> Csaba Nagy wrote:
> > I found that PITR using WAL shipping is not protecting against all
> > failure scenarios... it sure will help if the primary machine's hardware
> > fails, but in one case it was useless for us: the primary had a linux
> > kernel with buggy XFS code (that's what I think it was, cause we never
> > found out for sure) and we did use XFS for the data partition, and at
> > one point it started to get corruptions at the data page level. The
> > corruption was promptly transferred to the standby, and therefore it was
> > also unusable... we had to recover from a backup, with the related
> > downtime. Not good for business...
> >
> OK, but corruption at the data page level is a very unlikely
> event, isn't it ?
yes, and that is not a pitr problem, that is a data corruption
problem. i am very suspicious that slony style replication would
provide any sort of defense against replicating from a machine which
is changing bytes from a to b, etc. i think the best defense against
*that* sort of problem would be synchronous replication via pgpool.
merlin
