You need to map it in the file /etc/crypttab.

You want to configure your /etc/crypttab file to look like this:
lin-bak     /dev/sdb1 

On Sat, Jul 28, 2012 at 9:40 PM, Todd And Margo Chester <[log in to unmask]> wrote:
Hi All,

Xfce 4.8
Scientific Linux 6.2, 64 bit

I have just encrypted my backup drive.  Is there anyway
to get it into my fstab?

Problem is rebooting removed the label I created in
/dev/mapper with

     # cryptsetup luksOpen /dev/sdb1 lin-bak

and in fstab, I can add:
  /dev/mapper/lin-bak  /lin-bak  ext4  defaults  1 0

But "/dev/mapper/lin-bak" vanishes on me after a reboot.

I can double click on the icon on my desktop and
it will mount in "/media/lin-bak".  But this plays
havoc on my scripts.  Gives me a long funny name
in /dev/mapper too, which disappears when you
dismount.

Be nice to be able to get the drive into my fstab.
If not, how do I mount it from the command line?

If I try to mount directly, I get

     # mount  /dev/sdb1  /lin-bak
     mount: unknown filesystem type 'crypto_LUKS'

Perplexed,
-T