Block devices are files that refer to or represent a device. A block device could be anything from a hard drive, usb drive, flash drive, cd-rom e.t.c The lsblk command lists block devices.
lslbk
$ lslbk
lsblk lists information about all the available or specified block devices in a tree-like format.
NAME : This is the device name.
MAJ:MIN : This column shows the major and Minor device number.
RM : whether the device is removable or not. 0 indicates they are not removable.
SIZE : the size of the device.
RO : whether a device is read-only. RO=0 means they are not read only.
TYPE : whether the block device is a disk or a partition(part) within a disk. sda and sdb are disks while sr0 is read only memory (rom).
MOUNTPOINT : This column indicates the mount Point on which the device is mounted
lsblk -a
$ lsblk -a
lists all devices including empty ones.
lsblk -m
$ lsblk -m
list the ownership of a particular device as well as the group and the mode.
