Re: backups

Dennis Gearon wrote:

> What's LVM?

http://tldp.org/HOWTO/LVM-HOWTO/

LVM stands for Linux Volume Manager. It groups block devices (like hard
drives) into volume groups, then creates logical volumes on top of those
volume groups. In effect, it virtualizes away the nasty realities of
hard drives that don't dynamically change size, etc. and presents
"virtual" block devices to the OS.

One of the many wonderful features is that you can freeze one of these
virtual block devices ("logical volume" in LVM-speak) at a particular
instant in time, giving you a consistent view of that block device, and
any data on it, such as a filesystem. This is called a snapshot, and is
how, at our site, we get a consistent set of Postgres files to rsync from.

Regards,

Bill Montgomery