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I've got /dev/sdb1 encrypted and mounted as /home.

The following line is in /etc/fstab:

/dev/sdb1       /home           ext3    noauto,loop=/dev/loop6,encryption=AES128


#mount /home

works fine, but

#losetup -e encryption=AES128 /dev/loop0 /dev/sdb1

which I'm sure always used to work, gives:

ioctl: LOOP_SET_STATUS: No such file or directory, requested cipher or key length (128 bits) not supported by kernel

Does anyone know why? If the mechanism for aes encryption over loopback devices has been changed, how am I supposed to fsck such a drive?

share|improve this question
up vote 1 down vote accepted

If I'm not mistaken, -e is shorthand for --encryption. Try the next command instead:

losetup --encryption AES128 /dev/loop0 /dev/sdb1


losetup -e AES128 /dev/loop0 /dev/sdb1


$ losetup --help
 -e | --encryption <type> enable data encryption with specified <name/num>

Taken from the examples section of man losetup:

          # dd if=/dev/zero of=/file bs=1k count=100
          # losetup -e des /dev/loop0 /file
          Init (up to 16 hex digits):
          # mkfs -t ext2 /dev/loop0 100
          # mount -t ext2 /dev/loop0 /mnt
          # umount /dev/loop0
          # losetup -d /dev/loop0
share|improve this answer
Oops. I feel really dim now. Thank you very much. Assuming you don't mind, I'll ask for this question to be deleted, it's just noise. But thank you! – John Lawrence Aspden Mar 16 '11 at 21:32
Do not delete it, it can help people who look for the right syntax. This question is not dumb, this one is. – Lekensteyn Mar 16 '11 at 22:00

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