I'm looking at whether it is possible to perform a useful (i.e., reliably recoverable) online image disk/image backup of a PostgreSQL database. Is anybody doing anything like this already, either with FastBack, TSM or at a disk array level?

With MS SQL Server I can use TSM FastBack's VSS integration to create a consistent recovery point without taking the database down. Oracle gives me a hot backup mode to do the same. But I've not yet found anything that suggests it's possible to get a nice consistent backup using a disk image/split mirror backup using any tools, either via software or hardware/split mirror backups.

Has anybody tackled this before?
David Mc
London, UK