[SATLUG] Live backup / hot imaging software for Linux?

Matthew matthew at infodancer.org
Thu Feb 3 18:28:18 CST 2011

On 02/03/2011 04:19 PM, David Salisbury wrote:
> Can anyone recommend a good backup software that can clone an entire
> drive into an image while said drive is running?  Something like
> DriveImageXML, but for Linux.  I've tried just copying
> partition-to-partition (/dev/hda to /dev/hdb, for example) and using dd,
> with somewhat mixed and unpredictable results on the copy.  What is the
> best way to get a hot image of a disk in Linux?

There are lots of ways to do this, many of which have already been
discussed, but no one has mentioned the real solutions to your problem:
LVM, the Logical Volume Manager, and RAID.

Google gives me this fairly decent explanation for the LVM method:

The basic idea is to snapshot the volume you are running and then image
the backup in whatever way you choose.  Your snapshot will be
effectively frozen in time and won't be updated while your backup
process runs (which is likely what causes the inconsistencies you
mention).  You can mount the snapshot and tar or rsync it to whatever
location you choose.

You do need to be able to partition the drives with LVM in mind, however.

The other option (since you mentioned copying between two physical
devices) would be setting up those devices in a RAID1 array.  That would
maintain both drives as identical mirrors continuously and protect you
against either one failing.  It won't be a good backup solution if you
need to go back in time to recover deleted files or earlier versions of
files, but it protects effectively against disk failure and may be part
of the solution you are looking for.

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