Red Hat Bugzilla – Bug 216538
Lack of /dev/dm-? breaks hal's encrypted/LUKS volume support
Last modified: 2007-11-30 17:11:49 EST
Description of problem:
When I create a dm-crypt/LUKS device using cryptsetup a /dev/dm-? device node is
no longer created. This node was using by hal to determine the relationship
between a dm-crypt device and its backing device. As a result, dm-crypt/LUKS
devices are no longer mounted automatically by hal and friends.
I have been tracking Rawhide until Fedora Core 6. I am not sure when my system
stoped creating /dev/dm-? device nodes. I am also unsure what component was
responsible for this in the past.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Create a LUKS-encrypted removable disk
2. Plug the disk into a Fedora system
The hal and friends subsystem will detect a LUKS disk, prompt for a password and
setup a dm-crypt device. However, volume.crypto_luks.clear.backing_volume is
not set for the reasons listed above.
volume.crypto_luks.clear.backing_volume should be set and the device should be
I am using Fedora Core 6, with updates as of 18 Nov 06.
I found this bug when trying to work on my encrpyted root mkinitrd patch, bug
See hald/linux/coldplug.c and hald/linux/blockdev.c for references to /dev/dm-?.
This looks like a duplicate of bug 213801. :)
*** Bug 213801 has been marked as a duplicate of this bug. ***
This should fix the problem:
Comment out "KERNEL=="dm-[0-9]*", OPTIONS+="ignore_device"" in
/etc/udev/rules.d/50-udev.rules. Restart udevd. udevd should now create
I am not sure why udev has this rule.
Harald, do you have any comment onthis udev rule?
will release udev update soon.
Red Hat Magazine is scheduled to publish an article that talks about these
encryption features in hal. The publication date is estimated to be 25 January
07. Could you release a fix in udev before then?
already in the updates-testing repo
I tried udev-095-17.fc6.ppc.rpm from the updates-testing repository.
Unfortunately, I still find that /dev/dm-* devices are not created by udevd.
The following line seems to remain the culprit:
KERNEL=="dm-[0-9]*", ACTION=="add", OPTIONS+="ignore_device"
It seems that "ACTION==add" was added to this line, but the problem from before
With this line commented out, udevd creates /dev/dm-* as I would expect.
Confirmed. Still needed to patch by hand here, too :-(
*** This bug has been marked as a duplicate of 209590 ***
Note that this is fixed in F7. I can use my encrypted LUKS volumes just fine there.