Monday, April 23, 2012

HowTo: Linux List Disk Partitions Command

How do I list all hard disk partitions under Linux operating systems?

Usually, your hard disk drive divided into one or more logical disks called partitions. This division is described in the partition table found in sector 0 of the hard disk. The device is usually /dev/sda, /dev/sdb or so. A device name refers to the entire disk and the device name will be as follows:
  1. /dev/hd* - IDE disks. /dev/hda will be first IDE hard disk, /dev/hdb will be second IDE hard disk, and so on.
  2. /dev/sd* - SCSI or SATA disks. /dev/sda will be first SATA/SCSI hard disk, /dev/sdb will be second SATA/SCSI hard disk, and so on.
WARNING! These examples may crash your computer if NOT executed with proper care. BE EXTREMELY CAREFUL WITH THE FOLLOWING COMMANDS. ONE TYPING MISTAKE AND ALL YOUR DATA IS LOST.

List Partitions Under Linux

Open a terminal window (select Applications > Accessories > Terminal). Switch to the root user by typing su - and entering the root password, when prompted. Or use sudo command:
$ su -
# fdisk -l

OR
$ sudo fdisk -l
Sample outputs:
Disk /dev/sda: 251.1 GB, 251059544064 bytes
255 heads, 63 sectors/track, 30522 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0008fcd3
Device Boot Start End Blocks Id System
/dev/sda1 * 1 14 104448 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 14 13068 104857600 83 Linux
/dev/sda3 13068 13198 1048576 82 Linux swap / Solaris
/dev/sda4 13198 30523 139163648 5 Extended
/dev/sda5 13198 30523 139162624 83 Linux
The -l options shows the partition tables for the specified devices and then exit. If no devices are given, those mentioned in /proc/partitions (if that exists) are used. You can specify device name as follows (in this example list partitions for /dev/sda):
# fdisk -l

sfdisk Command

The sfdisk command act as a partition table manipulator for Linux. You can use this tool to list partitions too:
# sfdisk -l /dev/sda
# sfdisk -lu /dev/sda
# sfdisk -ls /dev/sda

Sample outputs:
71669760
Disk /dev/sda: 8922 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0
Device Boot Start End #cyls #blocks Id System
/dev/sda1 * 0+ 104- 105- 838656 83 Linux
/dev/sda2 104+ 235- 131- 1048576 82 Linux swap / Solaris
/dev/sda3 235+ 8922- 8688- 69781504 83 Linux
/dev/sda4 0 - 0 0 0 Empty
Where,
  1. -l : List the partitions of a device.
  2. -s : List the size of a partition.
  3. -u or -uS or -uB or -uC or -uM : Accept or report in units of sectors (blocks, cylinders, megabytes, respecpively). The default is cylinders, at least when the geometry is known.

Listing Linux a Partition Size Larger Than 2TB

The fdisk or sfdisk command will not list any partition size larger than 2TB. To solve this problem you need to use GNU parted command with GPT partitions. It supports Intel EFI/GPT partition tables. Partition Table (GPT) is a standard for the layout of the partition table on a physical hard disk. It is a part of the Extensible Firmware Interface (EFI) standard proposed by Intel as a replacement for the outdated PC BIOS, one of the few remaining relics of the original IBM PC. EFI uses GPT where BIOS uses a Master Boot Record (MBR). In this example list partitions on /dev/sdb using the parted command:
# parted /dev/sdb
Sample outputs:
GNU Parted 2.3
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted)
Set unit type to TB or GB by typing 'unit TB' or 'unit GB' at the (parted) prompt:
(parted) unit TB
OR
(parted) unit GB
To list partitions type print command at the (parted) prompt:
(parted) print
Sample outputs:
Model: ATA ST33000651AS (scsi)
Disk /dev/sdb: 3001GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
1 0.00GB 3001GB 3001GB ext4 primary
(parted)
To exit from parted session type 'quit' at the (parted) prompt:
(parted) quit

How Do I List All Partitions Layout On All Block Devices?

Pass the -l OR --list option to the parted command to lists partition layout on all block devices:
# parted -l
Sample outputs:
Show Linux Disk Partitions Command
Fig.01: Show Linux Disk Partitions With GNU parted Command


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