Dealing with EVMS issues

I was working on my laptop and realize that I was seeing the errors “device-mapper: ioctl: error adding target to table” and “device-mapper: table: 253:1: linear: dm-linear: Device lookup failed” flood my logs. My CPU usage was also extremely high. Apparently this is an issue with EVMS and recent Linux kernels. There are a couple ways to resolve this.

One way to resolve these problems is to simply remove EVMS from the system. I doubt many people actually use EVMS so this is recommended. Then if you were ever to decide to start using EVMS you could always reinstall the necessary packages. To uninstall:

• sudo apt-get remove --purge evms.*

For those that use EVMS or plan to use EVMS a deeper understanding of the problem is required. This issue arises from the fact that the Linux kernel (wisely IMHO) does not allow multiple “owners” of block devices. The EVMS documentation lists 3 ways to deal with this. The final option is a kernel patch which undoes this behavior that I would not recommend. The other 2 are:

1. Completely migrate to EVMS, such that all device references are prefixed by /dev/evms in all configuration files.
2. Add all devices not managed by EVMS to the the sysfs_devices.exclude line in the file /etc/evms.conf.

Regardless of which solution is taken, resolving this problem is highly recommended.

For more information:
* http://evms.sourceforge.net/install/kernel.html#bdclaim
* https://bugs.launchpad.net/ubuntu/+source/hal/+bug/124641
* https://bugs.launchpad.net/ubuntu/+source/udev/+bug/119315/