Hi, I am an LVM user and I have several LVM block devices on /dev/mapper/. I use most of them without a partition table inside them, so they just contain a filesystem and nothing more. Partitionmanager displays all of them in the list of devices, but in the main widget it treats the devices as if they had partitions, so it appends the number 1 to the name of the device, which results in an unknown device. For example, /dev/mapper/gkserver-home is displayed as /dev/mapper/gkserver-home1. As a result, all operations on this filesystem are impossible. For some reason it is able to detect correctly the filesystem, but not the label (for example, on ext3 the label takes the name "/sbin/e2label: No such file or directory while trying to open /dev/mapper/gkserver-home1 Couldn't find valid filesystem superblock.") Note: This happens with all versions I have tried, including beta3.
LVM (RAID, etc) block devices are not supported now. Hopefully at some point we will implement support but there is already another wishlist bug for that.