Failure to auto-load dm-mod kernel module

Bug #106696 reported by RW Penney on 2007-04-15
Affects Status Importance Assigned to Milestone
lvm2 (Ubuntu)

Bug Description

The libdevmapper package (1.02.08 in ubuntu-7.04-beta) does not auto-load the kernel dm-mod module either at system bootup, or when first used by a client application (e.g. cryptsetup, cryptmount). This means that those client applications will typically fail unless the user executes "sudo modprobe dm-mod" (or equivalents) beforehand. Clearly, it is far better that a common solution be implemented within the libdevmapper package rather than separately within each client of the libdevmapper library.

In the debian libdevmapper package, there is an /etc/init.d/libdevmapper script which executes "modprobe dm-mod" at system bootup, and this seems to work perfectly as a solution (provided the kernel doesn't auto un-load the module later - which I've not noticed on kernels up to 2.6.18).
Alternatively, one could perhaps patch the libdevmapper library itself to automatically execute the modprobe whenever a client application needs access to /dev/mapper/control.
A third possibility might be some form of udev rule triggered on access to /dev/mapper/control.

Without some form of fix to libdevmapper, usage of applications such as cryptmount, cryptsetup, dmsetup is always likely to be compromised.

Fixing this is likely to fix bugs 64625, 93568, 91405, 104452.

Dan O'Huiginn (daniel-ohuiginn) wrote :

Assigning to the kernel team; looks like this bug is fairly well described, and has several likely duplicates.

Changed in devmapper:
assignee: nobody → ubuntu-kernel-team
importance: Undecided → High
status: Unconfirmed → Confirmed
Changed in devmapper:
assignee: ubuntu-kernel-team → nobody

This is still in Hardy!

vamped (robert-strahl) wrote :

ditto JR, "This is still in Hardy!"

I'm using Ubuntu 8.04 64bit.

Daniel Hahler (blueyed) on 2009-02-22
Changed in devmapper:
status: Confirmed → Triaged
Phillip Susi (psusi) wrote :

I believe this was fixed some time ago. Is anyone still having this problem?

affects: devmapper (Ubuntu) → lvm2 (Ubuntu)
Changed in lvm2 (Ubuntu):
status: Triaged → Incomplete
Launchpad Janitor (janitor) wrote :

[Expired for lvm2 (Ubuntu) because there has been no activity for 60 days.]

Changed in lvm2 (Ubuntu):
status: Incomplete → Expired
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