Re: Filesystem level backup and 32 / 64 bit

Martijn van Oosterhout <kleptog(at)svana(dot)org> writes:
> On Tue, Mar 15, 2005 at 02:29:51PM +0100, NTPT wrote:
>> Is it posssible to take a "filesystem level backup" (copyiing all in=20
>> $PGDATA directory) from 64 bit system and use it as $PGDATA in the native=
>> 32 bit system with the same version of postgresql ?

> Doubt it, it's not explicitly supported. It might work, but padding
> changes, certain width changes, may screw you up.

It might work if the main server were compiled as a 32-bit application
... but AFAIK the Intel-ish 64bit architectures mostly suck in 32-bit
emulation mode, so you'd not want to do that. It will almost certainly
*not* work to just cram 64-bit files onto a 32-bit machine, because the
file layout is dependent on MAXALIGN which will likely be different.

> Use something like Slony, it's specifically supports this kind of
> usage...

Agreed.

regards, tom lane