Cannot close the mapping device with cryptsetup?

shams · 02-14-2014, 02:24 PM

I want to encrypt a partition with cryptsetup plain mode what i did is here:

Quote:

cryptsetup create /dev/sdc3
mkfs.ext4 /dev/mapper/crypt
mount /dev/mapper/crypt /crypt

The commands was successfull and asked for the passphrase and everything was done, i copy my data to the /crypt directory and umount the /crypt:

Quote:

umount /crypt

Now how to close the /dev/mapper/crypt device for the security reason that no one can mount it? and how i can open the device again to mount it?

mostlyharmless · 02-14-2014, 02:33 PM

cryptsetup luksClose /dev/mapper/crypt

to re-open

cryptsetup luksOpen /dev/sdc3 crypt

shams · 02-14-2014, 05:45 PM

Thanks for the reply, the first command luksClose working, but when i want to open the device get the error:

Quote:

# cryptsetup luksOpen /dev/sdc3 crypt

Device /dev/sdc3 is not a valid LUKS device.

metaschima · 02-14-2014, 08:57 PM

'cryptsetup remove' is the command to remove a device.

mostlyharmless · 02-15-2014, 03:14 PM

Might be the way it was created: I use
cryptsetup -s 255 -y luksFormat /dev/sdc3 to create the encrypted partition.
Warning: if you do that now it will wipe out whatever you put on sdc3