pvmove freezes system

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Environment

SUSE Linux Enterprise Server 10 Service Pack 2

Situation

An attempt to move Physical Volumes (PV) with the 'pvmove' command does hang. CTRL-C does not help to kill the process. This leads to a complete freeze of the system and only a hard reboot does help.

The command output might look like:

# pvmove /dev/sda6 /dev/sda7

system-pvmove0: device not found:

 /dev/sda6: Moved: 1.0%
 /dev/sda6: Moved: 1.8%
 /dev/sda6: Moved: 2.7%
 /dev/sda6: Moved: 3.5%
 /dev/sda6: Moved: 4.4%
 /dev/sda6: Moved: 5.2%
 /dev/sda6: Moved: 6.1%
 /dev/sda6: Moved: 6.9%
  ...
  ...

Resolution

Reboot the system and execute the command 'pvmove --abort' to abort any moves in progress.
Then make sure that "/var" and(or) "/var/run" are not stored on the PV devices which are involved in the 'pvmove' command, that is, the related Logical Volumes (LV) are not mounted under "/var" or "/var/run".

In fact 'pvmove' suspends all related dm table of logical volumes before it starts working, and as "/var" or "/var/run" are accessed during execution of this process, this leads to a deadlock.
If "/var" or "/var/run" have to be moved, it is recommended to boot into live CD first.

Disclaimer

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