Enterprise Backup Software with good support for LVM
Could someone suggest an Enterprise Backup package that has good support for LVM (LVM2 in this case) on Linux (Specifically Suse Linux Enterprise 9) Most products I've seen say they support block level backups but don't specifically say they support LVM.
Thanks,
-Mark
Quoted 4 lines · --On November 29, 2005 12:03:39 PM -0600 Mark F <[email protected]> wrote:
Could someone suggest an Enterprise Backup package that has good support for LVM (LVM2 in this case) on Linux (Specifically Suse Linux Enterprise
9) Most products I've seen say they support block level backups but don't specifically say they support LVM.
LVM provides a block level device. However you don't want to back up there anyway, you'll just end up with corrupt garbage. You need to back up at the filesystem level unless you're using your LVM LVs for Oracle or something similar in which case the backup software needs to support that by putting Oracle or the related application into the correct hot backup mode before attempting to directly read the LVM data, as well as backing up the transaction/redo logs.
Quoted 7 lines · Michael Loftis
LVM provides a block level device. However you don't want to back up there anyway, you'll just end up with corrupt garbage. You need to back up at the filesystem level unless you're using your LVM LVs for Oracle or something similar in which case the backup software needs to support that by putting Oracle or the related application into the correct hot backup mode before attempting to directly read the LVM data, as well as backing up the transaction/redo logs.
Surely by using snapshots, a block level backup could be "OK". You'd need to (ideally) tell the file-system layer to put the machine into a fit state to be snapshotted (quick & dirty, obviously issues with it, you could remount it readonly, snapshot, and then mount read-write again). It's also going to backup dead space, which is going to waste backup media (e.g. tape) at best, and leak information at worst.
If you have a journalling filesystem, then taking a snapshot of the active device would probably be acceptable... Not ideal, but depending on the relative importance of getting a perfect backup/restore and reducing the load on the system while the backup is being done, it might be acceptable to most people.
Obviously if your backup solution can tie into the filesystem's own backup utilities then you're going to get a better result, but for some people that's not the important thing (and not an option in backup utilities for others).
I know that dump/restore on solaris is unsafe to use on live partitions, I can't see any reference within the dump man pages to see if the same applies to linux, and have never used it in anger on an active filesystem - old habits die hard, so I do my best to keep it inactive when using it.
Graham
Quoted 10 lines · Michael Loftis
Quoted 4 lines · --On November 29, 2005 12:03:39 PM -0600 Mark F <[email protected]> wrote:
Could someone suggest an Enterprise Backup package that has good support for LVM (LVM2 in this case) on Linux (Specifically Suse Linux Enterprise
9) Most products I've seen say they support block level backups but don't specifically say they support LVM.
Quoted 9 lines
LVM provides a block level device. However you don't want to back up there anyway, you'll just end up with corrupt garbage. You need to back up at the filesystem level unless you're using your LVM LVs for Oracle or something similar in which case the backup software needs to support that by putting Oracle or the related application into the correct hot backup mode before attempting to directly read the LVM data, as well as backing up the transaction/redo logs.
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Our data center is using Veritas Netbackup (currently 4.5 but soon to be 5.1). We are preparing some new servers for production and would like to use LVM2 but I'm not sure if this will present a problem for the Veritas Netbackup agent. I don't know if the backup agent software will support it or if it will even know the difference.
Is anyone using it? Or does anyone have any reason to believe it will/won't work?
Thanks,
-Mark
Quoted 3 lines · Mark F
Michael Loftis wrote:
Is anyone using it? Or does anyone have any reason to believe it will/won't work?
Netbackup does a file level backup, rather than block level. This means that the filesystem used is not relevant, and the underlying structure even more so.
E.g. it works at the directory/file level - so it backs up the files that it finds and doesn't care what sort of block device is under that.
(That's assuming you're doing file backups, and not raw devices for DBs)