Public bug reported:
Binary package hint: mdadm
Release: Ubuntu 8.04.2, from alternate installation media. Probably also
affects Ubuntu 8.10.
Module: mdadm. Possibly affects others as well.
Version: 2.6.3. Probably also affects 2.6.7, which is used in 8.10.
Situation: I have installed \root and \swap to RAID 1 partitions with
encryption and LVM. When one of the RAID disks is missing from the
system, a prompt should ask whether I want to start with a degraded RAID
setup or not. Answering Yes should start up the system.
What happens: This depends on whether "quiet splash" boot options are in
use or not, as follows:
- When "quiet splash" is used, a prompt for LUKS encryption password appears
normally, but fails again and again even if the user types the correct
password. At this point the user probably thinks that the password is not
correct, or that there's something wrong in encryption. Both assumptions are
incorrect, as in fact there is nothing wrong with encryption nor the
password... Nevertheless, the system fails to start. By pressing CTRL+ALT+F1,
one can see these messages on screen, which also lead to wrong direction:
Starting up ...
Loading, please wait...
Setting up cryptographic volume md1_crypt (based on /dev/md1)
cryptsetup: cryptsetup failed, bad password or options?
cryptsetup: cryptsetup failed, bad password or options?
- Without "quiet splash" boot options, the user can observe system messages on
screen during boot process. At a certain point, the missing RAID disk causes a
long wait. During this wait, one can see these messages on screen:
Command failed: Not a block device
cryptsetup: cryptsetup failed, bad password or options?
... other stuff ...
Command failed: Not a block device
cryptsetup: cryptsetup failed, bad password or options?
Command failed: Not a block device
cryptsetup: cryptsetup failed, bad password or options?
cryptsetup: maximum number of tries exceeded
Done.
Begin: Waiting for root file system... ...
After a few minutes, the system prompts whether the user wants to start with a
degraded RAID setup. After answering Yes and another few minutes of waiting,
the system presents the command line (Busybox), ie. fails to start. This
happens probably because \root is encrypted and needs to be opened with a
password, however the password prompt already failed during the long RAID wait
period.
Note that it is possible to start the system from Busybox by typing
"cryptsetup luksOpen /dev/md1 md1_crypt", then typing LUKS password, and
finally pressing CTRL+D. This proves that the encryption works and the
problem is related to degraded RAID, handled by mdadm. Also the system
starts properly when all RAID disks are present; the problem only
appears with a degraded RAID.
More information:
For a long time, it was not possible to properly boot with a degraded RAID
setup. This bug was never present in Debian, only in Ubuntu. See bug 120375. A
solution was presented in 8.10, which was recently backported to 8.04.2. See
bug 290885. Apparently, encryption was not dealt with the fix, and thus this
bug likely affects all recent Ubuntu releases, including 8.10.
I consider this quite important to be fixed, as many RAID 1 users also
need to use encryption for protecting their data, especially in the
business world. Although there is a workaround for a starting the system
with degraded RAID and encryption, the error messages clearly lead to
wrong direction (encryption is not the problem), and even if the user
knows what's going on it is too complicated to look up the workaround by
googling in a stressing situation where a production server fails to
start.
Suggestions:
- When usplash is used, there should be a notification about a possible
degraded RAID array *before* LUKS encryption password is prompted, so that the
user has a possibility to figure out that the failure to boot is related to
RAID disks, not encryption
- When a degraded RAID is observed, LUKS password should actually be prompted
*after* answering the question for starting the system with degraded RAID
** Affects: mdadm (Ubuntu)
Importance: Undecided
Status: New
--
System startup fails with degraded RAID + encryption
https://bugs.launchpad.net/bugs/324997
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
--
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
