[dm-crypt] LUKS header always disappears after reboot

Cory Coager ccoager at gmail.com
Fri Jan 6 02:11:31 CET 2012

On 01/05/2012 03:11 AM, Arno Wagner wrote:
> Well, that is not a LUKS header, that looks like an EFI MBR
> or bootsector. There is no trace of the LUKS header.
> Either something is writing this to your disk
> or, if this is an USB disk, the USB-to-SATA controller in
> the disk may be doing this in violation of the spec, probably
> in a misguided atempt to make this thing usable under Windows.
> Is this really /dev/sdb1 and not /dev/sdb and is the partition
> still there?
> As to your data, unless you have a LUKS header backup, it is 
> very likely gone. 
> Here is something you can try: Zero the first GB or so of
> the drive, sync, reboot and see whether anything is on it.
> Then do the same, but unplug the drive while the computer
> is on and hotplug it after booting. And finaly do the same
> and unplug and replug the drive without booting the computer.
> That could give indication of whether the drive is doing 
> something by itself or whether the PC is writing something. 
> Arno
OK, I have a good deal of information of what the problem is.  The issue
seems to happen on two specific computers but not a third.  They aren't
recognizing the entire hard drive size.  fdisk is showing 3tb for
/dev/sdb but if I run fdisk on /dev/sdb1 it only shows 2199 GB for size.

Now, when I connected this drive to the third machine, it works
perfectly.  My data is still intact, I can see the LUKS header and I can
mount the file system.

Now that I've narrowed down the issue, how can I resolve it?  Why can't
these two computers see the entire drive size?

Both are custom builds, the drive was connected directly via SATA

Computer #1
Abit KN8 Motherboard
BIOS version 6.00 PG
AMD Athlon(tm) 64 Processor 3200+

Computer #2
Asus A8N32-SLI-Deluxe Motherboard
BIOS version 1303
AMD Athlon(tm) 64 X2 Dual Core Processor 3800+

Do you think I need a BIOS update or am I missing something in the OS?

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