I’m rebuilding my Mac and shuffling a lot of data. I have two 500GB external drives (one USB2 and one firewire). Currently the firewire drive is being used for backups and spends most of its time unplugged from a computer. I wanted to move my backup data from the firewire disk to the USB2 disk and use my firewire disk as a every-day-use drive. Since my plan with the backup disk is to leave it at the office most of the time, I want it encrypted.
My first attempt was to use the built in DiskUtil in MacOSX to create a 400GB exncrypted DMG file on the drive. This is clumsy looking and, it turns out, ridiculously slow (like 1.4 days slow). Mike had the suggestion to use TrueCrypt and so I did. This whole process tool about 10 minutes.
First I initialize the disk with TrueCrypt. TrueCrypt doesn’t have built-in support for formatting HFS+ volumes so we initialize it with no file system first.
jsc@melmac 1~% /Applications/TrueCrypt.app/Contents/MacOS/TrueCrypt -t –quick -v –random-source=/dev/urandom -c /dev/disk4s1
Volume type:
1) Normal
2) Hidden
Select [1]:
Enter system administrator password:
Encryption algorithm:
1) AES
2) Serpent
3) Twofish
4) AES-Twofish
5) AES-Twofish-Serpent
6) Serpent-AES
7) Serpent-Twofish-AES
Twofish-Serpent
Select [1]:
Hash algorithm:
1) RIPEMD-160
2) SHA-512
3) Whirlpool
Select [1]:
Filesystem:
1) FAT
2) None
Select [1]: 2
Enter password:
Re-enter password:
Enter keyfile path [none]:
Done: 100.000% Speed: 55.8 GB/s Left: 0 s
The TrueCrypt volume has been successfully created.
jsc@melmac ~%
Now I map the drive (without attempting to mount it):
jsc@melmac 127~% /Applications/TrueCrypt.app/Contents/MacOS/TrueCrypt
-t –filesystem=none /dev/disk4s1
Enter password for /dev/disk4s1:
Enter keyfile [none]:
Protect hidden volume? (y=Yes/n=No) [No]:
Enter system administrator password:
And now, finally, I can use diskutil to format it as HFS+.
jsc@melmac ~% diskutil eraseVolume "HFS+" "Jeff Clement Backup #1" /dev/disk5
Started erase on disk disk5
Erasing
[ \ 0%................................................... ]
From this point I can mount / unmount the TrueCrypt volume as normal. It just works. Way faster! Now I just have to shuffle some data around
Thanks Mike!