[DRBD-user] Lower device is already claimed. This usually means it is mounted.

Tomasz Chmielewski mangoo at wpkg.org
Fri Jun 13 18:22:17 CEST 2008

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

Paul J. Smith schrieb:
> Hi,
> I've got the problem on a box I'm building.  I've seen this problem mentioned quite a few times before, but none of the solutions seems to work for me.
> I do have data1-test which is one of my LVM logical volumes present in /dev/mapper.  I suspect, reading from other posts that this is preventing DRBR from accessing that partition.  In other threads I've seen that kpartx -d /dev/mapper/data1-test should fix this, but for me it does not and that mapping stays there.
> I'm running Ubuntu 8.04.
> Can anyone tell me if this is likely the cause, and how to remove the mapping?

Did you solve your problem yet?

1) ls /dev/mapper

Are there any nodes which end with partition numbers there (i.e, 1, 2 
etc.). These are the mappings.

2) Go to /etc/udev.

Look for multipath.rules, or a udev rule which looks similar to:

# multipath and multipath partitions nodes are created in /dev/mapper/
# this file should be installed in /etc/udev/rules.d

# take care of devmap partitioning
ACTION=="add", SUBSYSTEM=="block", KERNEL=="dm-*", \
        PROGRAM="/sbin/dmsetup -j %M -m %m --noopencount --noheadings -c 
-o name info", \
        RUN+="/sbin/kpartx -a /dev/mapper/%c"

Try to comment it out, and reboot your machine. Does drbd start now?

It may be that by commenting it out you won't see i.e. your LVM anymore, 
because it is also a mapping - in that case, add it manually (kpartx -a 
...) - generally, it will depend on your setup.

Tomasz Chmielewski

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