[Discuss] Filesystem(s) for multi-OS, whole house backup?

[dbarrett at blazemonger.com (Daniel Barrett)]

I'm seeking advice on disaster recovery for all the computers in my house
together (Linux, Windows, Mac), about 3TB of data.  Right now, I back up
all the computers via rsync each night, pulling the files from all the
systems into a Linux server that writes them to a USB ext3 hard drive. (I
can then put the drive into a safety deposit box.) Administratively, it's a
simple, scalable system controlled by a single computer: there's no
configuration on the other systems except SSH access. But it's not ideal
for several reasons:

1. Restoring the files is not point-and-click: you need Linux knowledge
(that my family doesn't have). If the computers were lost in a disaster and
also I died, my family would have a very hard time recovering files from
this drive. They can't just plug the USB drive into a Mac and recover
everything.

2. The backup is missing any extended file attributes from NTFS or Mac OS,
since the USB drive is ext3.

I'm wondering if other list members have a better solution. I can think of
several improvements, but I don't know which ones are best (or if there are
others):

Approach A: "ext3 everywhere." Install software on all Mac systems to read
ext3, and on all Windows systems to read ext3 and Mac. Now all systems can
read the backup drive in the event of disaster.

Approach B: "multiple filesystems and writers." Partition the USB drive to
have NTFS and Mac partitions, and mount it writable on all systems. Have
the Windows and Mac systems write their own backups to these partitions,
instead of having backups by "pull" onto the Linux server.  Probably also
requires Approach A so any computer can read any file.

Approach C: Start investigating systems like Bacula that claim to work on
all three OSes.  But I don't know if this produces, in the end, a USB drive
backup that can just be plugged into a Mac for restoral.

I should also mention that this USB drive is not my sole backup system.  We
also have a NAS that all the systems write to: the Macs use Time Machine
and the Linux & Windows systems using rsync. However, the NAS is too large
to keep in a safety deposit box.  I could copy the entire contents of the
NAS onto a USB drive for safety-deposit-box backup, I suppose.

I'd be grateful for any helpful advice or direction. Thanks.

--
Dan Barrett
dbarrett at blazemonger.com