
PGP rolls out Whole Disk Encryption for Mac - nickb
http://blogs.zdnet.com/BTL/?p=9037
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makecheck
I'm curious if full-disk encryption works with Time Machine. Since upgrading
to Leopard, Time Machine is one of my favorite features, and I know FileVault
users can't back up home directory files on Mac OS X.

In theory, there's no reason a file couldn't be backed up from one fully-
encrypted disk to another fully-encrypted disk, as long as the copy can be
authenticated.

But Time Machine likes to treat its target disk as "special"; I'm not sure if
this is simply due to the presence of "/Backup.db", or if the entire disk
needs special formatting.

Of course, if PGP is targeting the enterprise, businesses may already back up
their Macs in some other way and not care if Time Machine works.

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tlrobinson
I think the problem is that FileVault (and presumably PGP) stores your home
directory as one large file, so every time _any_ change is made to _any_ file
it has to backup the _entire_ home directory.

I have the same problem with Parallels images... any time a change is made on
Windows filesystem in Parallels the entire image needs to be backed up
(several GB). I ended up excluding the Parallels images from Time Machine.

