[SATLUG] Live backup / hot imaging software for Linux?
j at jvpappas.net
Sat Feb 5 19:30:42 CST 2011
On Thu, Feb 3, 2011 at 15:19, David Salisbury <
david.salisbury at momentumweb.com> 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
Assume FOSS: Acronis supports Linux, but is not FOSS.
dd won't result in a consistent point in time copy, so files and the
filesystem continue to change while the backup is running. You won't end up
with a "crash consistent" backup, so not really what you are looking for.
Matthew's reference to LVM is the best, as it uses a Copy on Write
snapshotting method, but requires said partitions be LVM, and moving from
static root to LVM root is non-trivial. I only install linux with LVM as it
allows for so much magic that I cannot stand static partitions for anything
but /boot and swap for laptop hibernation (thus my disks are
/dev/sd?1=/boot; /dev/sd?2=swap at 2xRAM; /dev/sd?3=LVM), and then at least LV
for root, home, additional swap (if needed), and any other breakout required
by the application (var, usr, opt, whatever)
In terms of a on-the-fly imager (ala Acronis or DIX) for static
partitions/disks, you need something that has/provides/uses snapshotting or
similar. I have no direct experience with any non-LVM snapshotting for
Linux, as most use cases allow for cold-clone so live snapshots gain little
benefit. For those use cases where live clone is needed, I use LVM.
I look forward to other's feedback and the potential solution (can't have
too many tools in one's toolbelt).
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