Let's establish a couple of assumptions. Do comment if those are not correct.
- you run machines with different operating systems, and potentially
different platforms.
- you describe it for the case with 2 machines, and Linux and FreeBSD
- your machines use encrypted filesystems
- you want to create backups of your data, and want those backups to be
encrypted too
- you want to be able to access data in those encrypted
backups from any of the platforms contributing to the archive
(comment added to make a distinction between forms of encryption)
You mention you would like to be able to access the others systems data, from the surviving machine. One way could be to store unecrypted backups, on the local machine, on it's encrypted filesystem. Another could be to store encrypted backups, on the local machine, on an not encrypted filesystem. I suggest to store encrypted backups, on not encrypted filesystems.
However, as an aside - there is always a concern over encrypted backups:
- you really need to be careful with the key
- partial corruption usually kills the whole backup
my suggestion: use
to create backups to one or multiple containers both machines can access.
To keep it all inside your LAN, you could:
- create a "backup" filesystem on both hosts, to store the encrypted backup "packages". It does not need to an be encrypted filesystem, as the backup "packages" (brackup calls them "chunks") stored on it will be encrypted
- export these filesystems, e.g. with NFS, and mount it on the other hosts, respectively
- when you create backups, dump them to the local filesystem, and mirror them to the NFS-mounted directory on the other host. This has the nice side effect of having two instances of your backup files.
you now will have the following filesystems on your servers:
on tux, your Linux machine:
/dev/foo / # encrypted filesystem
/dev/bar /tuxdump # unencrypted filesystem, local backup
beastie:/daemondump /daemondump # NFS backup destination
on beastie, you FreeBSD machine:
/dev/flurb / # encrypted filesystem
/dev/baz /daemondump # unencrypted filesystem, local backup
tux:/tuxdump /tuxdump # NFS backup destination
depending on the amount of data you need to backup, you could also think about an offsite container, any cloud provider would do. I'm currently playing around with configuring my S3 containers so that old stuff gets aged out to Glacier, that looks very promising, pricewise.
