[Discuss] Cloud-backup solutions for Linux?

[Rich Braun]

Daniel Barrett detailed his solution:
> I use a hybrid, multi-level process and haven't seen anything
> similar mentioned ... (We could improve by using an
> rsync+symlinks incremental approach.)

I have a couple of suggested improvements, since your solution's quite similar
to mine.  The rsync/symlinks approach is baked into rsnapshot, which you can
set up to run hourly: it's easy to figure out and has a simple config file.

One other tweak I have done is set up unison to run every 5 minutes between
pseudo-RAID1 mirrored volumes across two main servers.  I've tried various
other approaches trying to create a real clustered disk filesystem, but
settled on the tried-and-true unison.  (My last experiment, which I ran for
about 18 months, was GlusterFS--it was way too much overhead, and had way too
many undetected / disastrous split-brain situations that went on for days or
weeks.  After iterating on monitoring improvements several times, I declared
life-is-too-short-for-this.)

> all computers rsync onto a single USB3 drive, which rotates into
> a safety deposit box.

Alas nobody's come up with a properly automated way of doing physical vault
storage for the home yet (Iron Mountain has been doing this for offices
forever, in a way that's pretty seamless if your office has staffing to handle
daily UPS/Fedex deliveries--but it's expensive and not functional for home). 
I make do with a backpack of hard drives carried whenever I happen to remember
to swap them between locations.  Someday 15TB will fit in a thumb drive and
I'll do it more often.

> If Boston is nuked, the Linode files will survive, but the GPG keys
> won't.

I keep three copies of those (in my case, 2048-byte keys used for LUKS
encryption): I encrypt both the live filesystems and the backups, using a
separate key for each volume. Those copies are on USB thumb drives, one of
which is in a safety-deposit box and the others kept offline in locations
separate from the backup media (one of them carried with me on my keychain, at
least once I replace the one which just broke recently). A not-yet-solved
issue is that when I add a new volume, it's a pain to update all 3 thumb
drives so the one on my keychain tends to be the most current.

The other recommendations I make are to (a) write up detailed instructions on
how to restore from your backup, encrypt that file and make a printout to put
into your safe-deposit box, (b) go through the restore procedure with a
trusted technical friend, and (c) make sure your loved-ones who have entrusted
you with their data know about the safe-deposit box and the trusted-tech just
in case you get hit by a bus (or nuked).

-rich