[Borgbackup] Disaster Recovery or backup of backup

[Thomas Waldmann]

> Now that I'm going to set up two Backup servers with approximately 20 TB
> of backup data and roughly 40 clients each I wonder how to prevent data
> loss.

Are they at same place or different places? Mutual backup?

> Simply rsyncing all folders to a nas or something and setting up a new
> borg server won't work

Why?

> and two independent backups as suggested means to
> much traffic for the network as well as for some clients. There is
> simply not enough time for a double backup.

Did you actually try that? Except the first backup, backups are usually 
rather quick and not causing much traffic.

Do you use 1 repo per client?

> So, here comes my approach. I intend to use xen or better xcp-ng and on
> top the actual borg server as a VM. Snapshots/exports will be made every
> night and kept somewhere else. The data will be rsynced off the server
> too. In case of a disaster I just need a similar or identical HW, set up
> xen, import the saved VM and copy all the borg folders with the repos
> back. That way I'd have data and corresponding borg server put together
> again.

More complex, but you know better the effort you need to do to get it 
going again.

One can also recover from a full file backup of a simple linux system 
(no hypervisor, no VMs) using a usb live system, if you are used to it.

> Or I resurrect the server on some other xen host and access the
> data via nfs which would be quicker in case of an urgent restore.

That would mean the data goes over the network twice. Faster to get it 
up again, but if a big restore using that is faster in the end has to be 
seen. For normal production, I'ld avoid having the borg repo on NFS, but 
rather have it on local storage.


Besides the above, you could also prevent some issues:

Use zfs (mirror, raid-z6) so a single disk failure or bad sector does 
not cause a need for a recovery from backup. Also ECC memory, so RAM 
issues do not corrupt your backups.

Of course that is not a replacement for a 2nd backup, but reduces the 
frequency when you'll actually have to use it.


As the FAQ explains also, be careful with error propagation and crypto 
when using rsync to make repo copies.


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