On Tue, Oct 20, 2009 at 8:15 AM, Alex Dean
<alex@crackpot.org> wrote:
On Oct 20, 2009, at 10:00 AM, Matt Graham wrote:
From: Alex Dean <alex@crackpot.org>
Now, I'm trying to make a plan for those backups to survive the
house burning down or some other total catastrophe. I don't want
to lose 10 years of digital photos in an emergency like that, and
pushing all this data over my internet connection isn't feasible.
2 USB2 drives of sufficient size, rsync, and a friend who lives
at least a mile or 2 away. rsync the dirs containing backups of
the important junk to the USB drives. Give one drive to the friend,
keep the other at home. Every few days, rsync the drive you have at
home, then swap that drive with the drive your friend has. That
way, you lose at most a few days of data if your house burns down.
No net connection needed. All you need is a friend you see
regularly, or a secure storage locker you can get to every week.
Note that this might be difficult or expensive if you have more than
2T of data to back up. You can also use dm-crypt on the backup USB
drives for additional security.
I liked the idea of swapping out the spare RAID drive, since then the 3rd drive would always be up-to-date whenever I decided to swap disks. With rsync, I'll need to schedule the job ahead of time, and wait for it to finish before swapping. That's really not a huge problem. Having the drives accessible via USB also makes them more accessible from other systems if disaster really does strike, and that's worth something.
I'm now weighing the rsync+USB drive option against cold-swapping the spare drive in my RAID array. Powering off the backup server to change drives is not a big deal, though a hot swap would definitely be nicer.
alex
I do the backup to usb using rsync method for backups in a couple of offices and it works well.
In addition to making a mirror it creates a tarball of the day before.
I opted to format the drive as Fat32 which allows them in the event of failure
to plug the usb drive into any computer and get back to work.
The downside is that you can't set permissions like you could on a linux file system.
They have two usb drives that they swap out once a week (an employee takes it home)
it's been going that way for years. We even used it to create a new server a few states away to also rsync with.
One gotcha is that depending on where they plug it in it can be sda, sdc, sdd etc. I wrote a script to figure out where it is before mounting it. It's been working great for years. Usually I pair that technique with an on-site or off site backup server also.