On Dec 11, 2007, at 1:21 PM, Josh Wisenbaker wrote:
I've been wondering why Apple imposed that restriction, as I
cannot identify a technological limitation that would preclude
active backups (or TM browsing) by a logged-in FV user. I haven't
played with TM (or 10.5) in my office much, but on my personal
computer I have noticed that I can easily mount the diskimage on
my FV drive and browse its contents. So if I can access the image,
why can't Time Machine?
TM does FileVault backups like it does as otherwise your TM disk
would be a nice, unencrypted, history of all your data.
I understand why it uses an encrypted image. What I don't get is why
it cannot read or write from/to that image when I am logged in. I
can access that image from the Finder... I would think TM could
acquire my privileges and access it as well.
Wouldn't the reason why TM and FireVault'ed homes are not compatible
be more due to the fact that when you log out your home directory
disappears (gets unmounted)? It was probably too difficult a problem
for TM to handle that transition, so they decided just to say that
it's not something you can do.
If you recreate your FileVault on 10.5 it should be a tiny bit
faster as it will use a sparsebundle image rather than a vanilla
sparse image.
IIRC, Time Machine forced me to update my FileVault (not an easy
task, since rarely is there enough free space on a power user's
personal laptop to de-encrypt and re-encrypt the primary user)
before it would consider backing up my user data. It gave a cryptic
message to that effect *once* and then behaved as if it was backing
up everything, while in fact it was backing up the system, but not
my account.
-----
- Peter Schwenk
- CITA-3, Systems Administrator
- Mathematical Sciences
- University of Delaware
- schwenk _at_ math _dot_ udel _dot_ edu
- http://www.math.udel.edu/~schwenk
