Re: [rdiff-backup-users] operational questions

[John Labovitz]

On Apr 27, 2004, at 10:17 AM, Eric S. Johansson wrote:

> any suggestions for somehow protecting rdiff backed up data on a 
> friendly foreign machine?

Two possibilities, off the top of my head --

1. Use an encrypted sparse file image on the foreign machine.  This 
will let you have a file system that, when unmounted, is a big blob of 
a file.  (See Disk Utility and "hdiutil" for more details.)  However, 
you'll have to find a way to mount/unmount the image when the remote 
rdiff-backup logs in.  You might be able to use ssh "subsystems" to do 
this -- see "man sshd_config".

However, I see two holes with this: first, once the image has been 
mounted, the files on it are readable to the admin of the foreign 
machine.  So it's not completely opaque.  Secondly, it seems fairly 
possible for the connection to die in such a way that the image is 
never unmounted -- leaving it open again.

2. Use rdiff-backup to a *local* encrypted sparse image, then use rsync 
to mirror changes in that image over to the foreign machine.  (Rsync 
has a --sparse option that may work well here.)

The obvious disadvantage with option #2 is that you have to store your 
diffs locally. It also may require a large diff, since at least parts 
of the sparse image are being completely re-encrypted.

Again, I haven't really tried either of these -- just throwing them out 
as ideas.

--
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