The first argument to dmsetup is a command. The second argument is the logical device name or uuid.
Invoking the dmsetup tool as devmap_name (which is not normally distributed and is supported only for historical reasons) is equivalent to dmsetup info -c --noheadings -j major -m minor.
Each line of the table specifies a single target and is of the form:
logical_start_sector num_sectors target_type target_args
Simple target types and target args include:
More complex targets include:
To find out more about the various targets and their table formats and status lines, please read the files in the Documentation/device-mapper directory in the kernel source tree. (Your distribution might include a copy of this information in the documentation directory for the device-mapper package.)
# A table to join two disks together 0 1028160 linear /dev/hda 0 1028160 3903762 linear /dev/hdb 0 # A table to stripe across the two disks, # and add the spare space from # hdb to the back of the volume 0 2056320 striped 2 32 /dev/hda 0 /dev/hdb 0 2056320 2875602 linear /dev/hdb 1028160
Original version: Joe Thornber <email@example.com>
dmstats(8), udev(7), udevadm(8)
LVM2 resource page: https://www.sourceware.org/lvm2/ Device-mapper resource page: http://sources.redhat.com/dm/