Tom Korach <tom@safekeep.com> writes:
>> What do you mean exactly by "file-system replication"?
> RAID1 setup (specifically, between two disks or EBS volumes [on AWS]),
> using LVM.
Maybe I'm missing something, but AFAIK plain old RAID will not protect
you against any scenario except failure of a single disk. It certainly
won't do anything to help you revert to a prior database state.
The docs page I pointed you to is part of a chapter that lays out all
the backup methods the PG community considers reliable. I strongly
suggest sticking to one of those and not trying to take shortcuts.
(The following chapter on high-availability setups is relevant
reading as well.)
regards, tom lane