XenEnterprise, Dapper and evms
If you get a couple errors like dm-linear: Device lookup failed or mount: /dev/sdc1 already mounted or /export busy on XenEnterprise with Ubuntu Dapper, I suggest: apt-get remove -\-purge evms. See this bug report for some extra details.
I stopped using evms many years ago when it corrupted some of my data, lvm by itself its a much better system. I wish Ubuntu wouldn’t include it by default.