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Timmy
03-04-2005, 09:37 AM
If I perform a full backup while logged into a user account that utilizes FileVault, what will the resulting back-up disk look like?

Thanks,
Timothy

dnanian
03-04-2005, 09:42 AM
In general, Timothy, you should create a non-FileVaulted account to perform backups from. While you *can* back up a FileVault account from "inside" it, the resulting backup has the hidden FileVault volume "mounted", so logging into that image in a recover situation can be weird.

If you log out and into a non-FV account, the image is closed and "put away", and the backup is a lot "cleaner".

Note that, as you'd probably expect, Smart Update doesn't work as well with FileVault. Since your user files are stored in one "big image" under FileVault, that entire image needs to be backed up each time any files on it change. That takes a lot more time than, say, just backing up a modified document.

Timmy
03-04-2005, 09:56 AM
While you *can* back up a FileVault account from "inside" it, the resulting backup has the hidden FileVault volume "mounted", so logging into that image in a recover situation can be weird.

Yeah, I'm having a tough time wrapping my brain around this scenario... :confused:

So, the FileVault .sparseimage would be 'open' on the backup all of the time?

If you log out and into a non-FV account, the image is closed and "put away", and the backup is a lot "cleaner".

Would Fast User Switching over to the non-FV account be sufficient, or should it be a regular log out/log in?

Thanks for your help with this,
Timothy

dnanian
03-04-2005, 10:25 AM
It's not so much that it'd be "open", but OSX does some strange things when you log into a FileVault account to "fool" the system into thinking your files are local. Basically, they mount a special volume and then "link" it to your home folder.

The special volume is stored on the drive, but in this linked situation, it's in an "open" configuration, rather than "closed" (like when you log out).

So, to get it to be as it would be when you reboot -- the safest configuration -- it's best to log out and into a non-FV account. This closes the volume and puts its away, ensuring that the backup proceeds as if your computer was turned off. That way, when you boot from the backup, it's as if you had started from a power-off situation, rather than from logged-in.

FUS isn't enough, unfortunately, because the volume isn't closed.

Timmy
03-04-2005, 10:33 AM
Thanks for taking the time to explain this, Dave!

Regards,
Timothy

dnanian
03-04-2005, 10:42 AM
No problem. It's a reasonably common question, and I should probably write a FAQ about it!

Stoopidlie
07-12-2005, 08:18 PM
I agree. This should be an FAQ and appear in the User's Guide. I'm a Filevault user too and could not figure out why I was running out of space on my target drive when I did a Smart Update. (I had not even reached the point of discovering I had a funkily backed up FileVault sparseimage.)

--Marc

dnanian
07-12-2005, 08:26 PM
It's going to appear in the User's Guide. It isn't asked very frequently, though, which is why it's not in a FAQ...