On 03/14/2012 02:59 PM Nataraj wrote: > On 03/14/2012 08:43 AM, Les Mikesell wrote: >> On Wed, Mar 14, 2012 at 10:10 AM, ken <gebser at mousecar.com> wrote: >>> What (FOSS) backup apps can back up a system running at level 3/5? >> Almost all backup methods except raw partition/disk images will work >> with the system running. You aren't guaranteed that files will be in >> a consistent state when restored, but the OS itself is fairly sure to >> work and databases and similar apps usually have their own ways to do >> live consistent snapshots. >> > I find that LVM snapshots are useful to insure data integrity. for > example, I backup my mysql databases by stopping the mysql server, > taking an LVM snapshot and restarting it. The whole snapshot process > probably takes less then 15 seconds. Then I backup the snapshot LVM and > it doesn't matter how long it takes. You must make sure that your > snapshot volume is large enough that you won't run out of space before > deleting the snapshot. > > Nataraj Thanks for the tip. The details of how a snapshot works has long evaded me. For example, when files are open but unsaved, what is written to the snapshot...? And is the entire contents of a file recorded by the snapshot... or something else? tia.