Disk management on linux

Commands such as checking, adding or removing storage devices, creating and deleting partitions.

In this article, I resume some bash commands to check up or manage partitions on a linux system. The commands would check what partitions there are on each disk and other details like the total size, used up space and file system etc.

List block devices lsblk

lsblk lists the different partitions and block devices in the system with their ids. The command prints all block devices (except RAM disks) in a tree-like format.

lsblk

Mount a disk

We have to create a directory which will be the mount point for the device. The command mount mounts the device to the mount point.

sudo mkdir /{your directory name here}
sudo mount /dev/{specific device id} /{your directory name here that is already created}

unmount a disk

umount command unmounts any mounted filesystem on your system. It requires disk name or mount point name to unmount currently mounted disk.

sudo umount /dev/sdb

Permanently mount a disk

Set the system so that your devices will be automatically mounted. All information about device, format and mountpoint can be checked on /etc/fstab

cat /etc/fstab

To add a new drive to the mounted devices, edit /etc/fstab

sudo vi /etc/fstab

This file is a table of 6 columns, each row describes a mounted devices.

1. Device specifies the mount device. These are usually device filenames. Most distributions now specify partitions by their labels or UUIDs.
2. Mount point specifies the mount point, the directory where the partition or disk will be mounted. This should usually be an empty directory in another file system.
3. File system type specifies the file system type i.e. ext4
4. Options specifies the mount options. Most file systems support several mount options, which modify how the kernel treats the file system. You may specify multiple mount options, separated by commas.
5. Backup operation contains a 1 if dump should back up a partition or a 0 if it shouldn’t. If you never use dump you can ignore this option.
6. File system check order specifies the order in which fsck checks the device/partition for errors at boot time. A 0 means that fsck should not check a file system. Higher numbers represent the check order. The root partition should have a value of 1 , and all others that need to be checked should have a value of 2.

Once, fstab is filled, we have to test it.

sudo mount -a

If this command works, then we can reboot the system. By experience, errors returned by mount is often due to a bad file system type.

sudo reboot