12 Replies Latest reply: Feb 28, 2008 8:29 PM by J Michael
J Michael Level 3 (645 points)
I've got a 250 GB drive on my MBP, and 220GB is used. I decided to use FileVault to encrypt my Home folder but it says I need 157GB more space. Does it need as much empty space on the drive, as is used by the Home folder? If so, that pretty much defeats the purpose of the product.

MacBook Pro with lots of extra stuff, Mac OS X (10.5.2), iPhone in pocket, iPod in car, Nikon and Adobe everything
  • Niel Level 10 (293,590 points)
    Does it need as much empty space on the drive, as is used by the Home folder?

    Yes. A second copy of the home folder is created during the process of turning FileVault on and off.

  • William Lloyd Level 7 (21,030 points)
    Your disk is to full to do the Filevault conversion at this time. If you clear enough space to do the conversion you can copy the stuff back at that point... FileVault of itself doesn't take much if any more space than not using it.

    That said... with a 250 GB drive and 220 GB in use... you're running close to where you'll start running into performance issues. It's generally a bad idea to let a drive get more than 85% full.
  • joshz Level 4 (3,280 points)
    Also, FileVault is absolutely NOT necessary for the average user. According to most apple representatives, it is meant for government users only, or those with state secrets on your drive. With FileVault, you are basically entrusting ALL your data to ONE file-a disk image. If it gets corrupted, you lose all your data. Also, with FileVault, Time Machine CANNOT back up your home folder unless you are logged out.

    If you do have data you need to secure, then make individual encrypted disk images with Disk Utility (/Applications/Utilities, File>New>Blank Disk Image, and select, under encryption "128-bit AES Encryption").

    Good luck!
  • J Michael Level 3 (645 points)
    Thanks for the advice - however, I want on-the-fly encryption, not selective. And I don't have the time (or the presence of mind) to use the disk utility or one of the freeware versions like Encrypt This. I could live with Folder encryption whereby a folder such as my Documents folder is entirely encrypted. I actually have a fair amount of sensitive information on my MBP and don't want to lose it if I lose the computer OR if I lose my 2.5" external bootable clone drive, which I carry with me in case of primary drive failure.
  • Tim Campbell1 Level 3 (575 points)
    As I tell everyone who is interested in using FileVault.... you are only a candidate for FileVault if you have the discipline to run regular backups. It sounds like you do since you say you have a backup boot drive.

    But...you mentioned that you take this backup boot drive with you. If you run FileVault, that's a bad idea.

    Time Machine does a lousy job with FileVault because it backups up the whole sparse image as an encrypted blob. It takes a lot of space, but worse is if you want to restore a file you end up having to restore the whole FileVault for that day. While you can get back what you lost, you might (probably will) end up over-writing files you didn't want over-written. You end up playing a big shell-game trying to restore your files without having the undesirable side-effect of wiping out files you did not want to restore.

    This leaves you with options of backup programs that make non-encrypted backups. I use "SuperDuper!". it's easy, clever, and makes a full bootable backup kept up-to-date but only takes the time needed to do an incremental backup. Unfortunately since FileVault is 'transparent' to the user in that you and your applications wont really notice that your home directory is encrypted, neither does your backup program. THAT means that your backup is actually not encrypted at all. That fixes the whole restore headache that Time Machine has with FileVault, but unfortunately if you carry this backup disk around with you and someone steals your laptop bag (with backup drive) then they have an non-encrypted copy of your data... which sort of defeats the whole point of using FileVault.

    So DO make backups... just DO NOT carry them with you.


    Message was edited by: Tim Campbell1
  • J Michael Level 3 (645 points)
    Actually, I use Super Duper also. I like it, but my external drive is vulnerable. You say to not bring one's external backup with you. That defeats the purpose of having a backup, if one travels. I need a cloned drive that I can boot from when I'm traveling, if the main drive fails. I have other 3.5" desktop drives in safe locations for archiving. But the 2.5" one, I need to take with me.

    I do not use Time Machine for the simple reason that it does not create bootable clones. I have no interest in being able to go back to various periods. I do a daily backup with Super Duper and that works fine (except that someone else could access the information, even without the basic password authentication that they need to get in to the OS!)
  • dwb Level 7 (22,240 points)
    Sounds like you and I are fairly similar in our needs. I came to distrust file vault early on, to the extent that I refer to it today still as vile vault. If it becomes corrupt or if you develop a problem that involves your library folder things get ugly. If you insist on using it, make sure you have a second admin account already made to log into in an emergency.

    Instead of using file vault, I created a sparse image disk image with password protection. I keep it in my documents folder and put it on my dock to open it when I need it. (For a time I was using a short simple AppleScript to trigger its opening when I logged on but decided that was a little insecure for my purposes.) A nice side benefit is that by encrypting only those files that actually need it, I can carry my vital files in a flash drive when I need to travel with a backup.
  • J Michael Level 3 (645 points)
    Thanks - can you explain more how the sparse image works? Is it an encrypted 'folder' that I can open, add files to and from, then close again?
  • dwb Level 7 (22,240 points)
    Open up the Disk Utility program (inside your Utilities folder). In the top bar is a button *New Image*. You'll see options for size, encryption, etc. Look in help to learn more about your options. While a disk image can be resized manually with Disk Utility, the advantage of a sparse image is that it grows as you add items to it without any intervention. (Though it doesn't shrink on its own.) Since so much software is delivered in disk images today, you are already familiar with them, right? Double-click on a disk image and it mounts a drive on the desktop. Eject it and its gone.
  • J Michael Level 3 (645 points)
    Yes, I'm familiar with disk images. But my question is still, can I open the image, add files to and from, then close it again? And, in so doing, does it save the files that have been added to it?
  • Niel Level 10 (293,590 points)
    But my question is still, can I open the image, add files to and from, then close it again?


    And, in so doing, does it save the files that have been added to it?


  • J Michael Level 3 (645 points)
    Very cool. I'll try it...