Linux Commands - Disk Commands
- Commonly used flags:
- -h : Display result in human readable format.
- -T: Display the file system type.
- df [fileName]: Display information about the file system containing the provided file name or directory
- Example Command:
- Commonly used flags:
- -h: Human readable format
- -s: Summarize i.e display one total for each argument.
- -c: Prints grand total.
- -L: Follows symbolic links and calculates the disk usage of target files or directories.
- Example:
- Commonly used flags:
- -a: Display all available block devices
- -p: Prints full device path for each device.
- Example:
- Commonly used flags:
- -l: Lists the partition table of all attached system on your system.
- p: Prints the partition table.
- n: Creates a new partition table.
- Example:
- Commonly used flags:
- -t: Type of filesystem
- -V: Produce verbose output.
- Example:
- Commonly used flags:
- -t: Type
- —move: Move mounted tree to another place.
- Example:
mount: It is used to mount a filesystem or a device to a specific directory making its content accessible to the user.Basic Syntax: mount [OPTIONS] DEVICE MOUNTPOINT
mount /dev/sdb1 /mnt
#view details
mount -l
#result
/dev/sdb1 on /mnt type ext4 (rw,relatime)
Note: Similarly to unmount we can use umount /mnt.
mkfs: It is used to build a linux filesystem on device partition or a specific device.Basic Syntax: mkfs [OPTIONS] DEVICE [SIZE]
#create ext4 filesystem in previously created partition table {/dev/sdb1}
mkfs -t ext4 /dev/sdb1
#result
mke2fs 1.45.5 (07-Jan-2020)
Creating filesystem with 786432 4k blocks and 196608 inodes
Filesystem UUID: 5053f768-cdb0-40ca-829b-72f1d4e4e6aa
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Allocating group tables: done
Writing inode tables: done
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done
fdisk: It is used for managing disk partitions. It allows you to create, delete, modify, and display information about disk partitions on your system.Basic Syntax: fdisk [OPTIONS] DEVICE
fdisk /dev/sdb
#result
Command (m for help): **n**
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p): **p**
Partition number (1-4, default 1): **1**
First sector (2048-10485759, default 2048):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-10485759, default 10485759): **+3G**
Created a new partition 1 of type 'Linux' and of size 3 GiB.
Command (m for help): **p**
Disk /dev/sdb: 5 GiB, 5368709120 bytes, 10485760 sectors
Disk model: VMware Virtual S
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x83eb5a76
Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 6293503 6291456 3G 83 Linux
Command (m for help): **w**
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
#Note: All the user inputs are highlighted bold
lsblk: Lists information about block devices. The command prints all block devices (except RAM disks) in a tree-like format by default.Basic Syntax: lsblk [OPTIONS] [DEVICE...]
lsblk -p
#result
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
/dev/loop0 7:0 0 61.9M 1 loop /snap/core20/1328
/dev/loop1 7:1 0 67.2M 1 loop /snap/lxd/21835
/dev/loop2 7:2 0 53.3M 1 loop /snap/snapd/19361
/dev/loop3 7:3 0 53.2M 1 loop /snap/snapd/19122
/dev/loop4 7:4 0 63.5M 1 loop /snap/core20/1891
/dev/loop5 7:5 0 91.9M 1 loop /snap/lxd/24061
/dev/sda 8:0 0 20G 0 disk
├─/dev/sda1 8:1 0 1M 0 part
├─/dev/sda2 8:2 0 1.5G 0 part /boot
└─/dev/sda3 8:3 0 18.5G 0 part
└─/dev/mapper/ubuntu--vg-ubuntu--lv 253:0 0 18.5G 0 lvm /
/dev/sr0 11:0 1 1.2G 0 rom
du: It estimates file and directory space usage. It is used to check the size of individual files or directories.Basic Syntax: du [OPTIONS] [FILE...]
du -shc backupScript/ ca/ cust_data.sql
#result
4.0K backupScript/
32K ca/
204K cust_data.sql
240K total
df: It displays the amount of disk space available on the file system containing each file argument. If no any file name is given then it will show the space available on all currently mounted file system.Basic Syntax: df [OPTIONS] [FILESYSTEM...]
df -Th
#result
Filesystem Type Size Used Avail Use% Mounted on
udev devtmpfs 921M 0 921M 0% /dev
tmpfs tmpfs 194M 1.4M 192M 1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv ext4 19G 6.5G 11G 38% /
tmpfs tmpfs 966M 0 966M 0% /dev/shm
tmpfs tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs tmpfs 966M 0 966M 0% /sys/fs/cgroup
/dev/loop0 squashfs 62M 62M 0 100% /snap/core20/1328
/dev/loop1 squashfs 68M 68M 0 100% /snap/lxd/21835
/dev/loop2 squashfs 54M 54M 0 100% /snap/snapd/19361
/dev/loop3 squashfs 54M 54M 0 100% /snap/snapd/19122
/dev/loop4 squashfs 64M 64M 0 100% /snap/core20/1891
/dev/loop5 squashfs 92M 92M 0 100% /snap/lxd/24061
/dev/sda2 ext4 1.5G 209M 1.2G 16% /boot
tmpfs tmpfs 194M 0 194M 0% /run/user/1000