I have found two problems in LVM2/DM w/ a potential new "experimental feature" in 2.6.28: CONFIG_DEBUG_BLOCK_EXT_DEVT (this is from Jens Axboe's origin/for-2.6.28 git branch) "Conventionally, block device numbers are allocated from predetermined contiguous area. However, extended block area may introduce non-contiguous block device numbers. This option forces most block device numbers to be allocated from the extended space and spreads them to discover kernel or userland code paths which assume predetermined contiguous device number allocation." W/ LVM2 & DM there are (at least) two issues: (1) Device major numbers for some reason are /not/ being entered correctly into /proc/devices -- w/ CONFIG_DEBUG_BLOCK_EXT_DEVT=y I am seeing some devices w/ major "259" (a SATA controller) but no entry in /proc/devices. LVM2/DM will not find the entry in /proc/devices, and not allow any device w/ that major to be used with LVM commands. (2) Device minor numbers can be quite large, and the 10-character limits in dm/lib/libdm-deptree.c are too small. Alan -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel