[linsomniac]

If you want to do similar for block devices: https://github.com/rolffokkens/bdsync

I use it to back up a few virtual machines that, in the event of a site loss, would be difficult to rebuild but also critical to getting our developers back to work. I take an LVM snapshot of the VM, then use bdsync to replicate it to our backup server, and from there I replicate it off to backblaze, then destroy the snapshot.

[OrangeDelonge]

How does this compare to drbd?

[linsomniac]

DRBD is more of a live sync, and it's great stuff, as long as you set it up BEFORE you need it, and you need it frequently. If you want to keep a second copy of your data on another system, up to the second(ish), it's a great choice.

If, however, you just want a copy of a block device on another system, like for weekly backup (our case), it's probably overkill. Especially as to keep it truly consistent you need to run in the mode where writes are acked only once the remote AND local devices have it.

My VMs are running on ganeti, which has a mode where the backing device can be DRBD and written to another host. Which works great if you have the extra disc space and can deal with the latency. Also allows you to live migrate VMs between the two hosts.

In my case I ultimately want the copy off-site, so DRBD isn't really a great fit.

DRBD is very good stuff though, I've used it for decades for HA database servers and the like.