lsblk Command

Purpose

Lists block devices such as disks, partitions, LVM, RAID, loop in a tree-like or list format with detailed system information.

Syntax

lsblk [ -a ] [ -b ] [ -d ] [ -D ] [ -e ] [ -f ] [ -h ] [ -i ] [ -I ] [ -J ] [ -l ] [ -m ] [ -n ] [ -o ] [ -O ] [ -p ] [ -P ] [ -r ] [ -s ] [ -S ] [ -t ] [ -T ] [ -V ] [ -x ] [ -z ]

Description

The lsblk command lists block devices such as disks, partitions, LVM, RAID, loop in a tree-like or list format with detailed system information. In PowerVC virtual appliance, only read-only display is allowed for security. Device modification, mounting, or writing is not allowed.

Flags

Table 1. Flags
Item	Description
-a or --all	Lists all devices, including empty, holder-less, or disabled devices. For example, unpartitioned disks, loop devices without backing files.
-b or --bytes	Prints the capacity in raw bytes instead of human-readable format. For example, the capacity is displayed as, 2000398934016 instead of 1.8 T. This option is ideal for scripting.
-d or --nodeps	Lists only the base devices. For example, this option shows /dev/sda but does not list its partitions.
-D or --discard	Displays information about discard (TRIM) capabilities of block devices. For example `DISC-ALN`, `DISC-GRAN`, `DISC-MAX`, `DISC-ZERO`.
-e `list` or --exclude `list`	Lists devices by excluding the devices based on the specified major device number. The `list` is comma-separated major device numbers that must be excluded. If no major device number is specified, the RAM disks (1) and loop disks (7) are excluded by default.
-f or --fs	Displays the file system information. For example, `FSTYPE`, `LABEL`, `UUID`, `MOUNTPOINT`.
-h or --help	Displays help about the lsblk command.
-i or --ascii	Uses only ASCII characters for tree lines. This option does not use the UTF-8 box-drawing characters. The output of this option is safe for logs and scripts.
-I `list` or --include `list`	Displays the devices with the specified major device numbers. The `list` is comma-separated major device numbers for which the information must be displayed.
-J or --json	Redirects the results in a JSON format for scripting and automation.
-l or --list	Displays the output in a list format. This option displays information about one device per line. The output of this option is easier to parse.
-m or --perms	Displays the devices along with their file system permissions. For example, `OWNER`, `GROUP`, `MODE` of device nodes.
-n or --noheadings	Displays the device list without the column headers in a simple format. Then output of this option is ideal to work with grep or awk command.
-o `column_list` or --output `column_list`	Displays device information only for the specified columns headings. A list of column headers can be specified separated by commas. For more information about the available column headers, see Column headers.
-O or --output-all	Displays all the available columns.
-p or --paths	Displays the full device paths. For example, this option displays /dev/sda1 instead of sda1.
-P or --pairs	Displays the device information as `Key="value"` pair. The information is displayed one line at a time. This option is idle for shell parsing.
-r or --raw	Displays raw output. The output is not aligned. Only minimum formatting is done to the data.
-s or --inverse	Display device information in an inverted, dependency-based order. The lsblk command prints the mount point or partition first, followed by the physical disk it resides on, reversing the standard output tree.
-S or --scsi	Displays only the Small Computer System Interface (SCSI) devices.
-t or --topology	Displays I/O topology. For example, `ALIGNMENT`, `MIN-IO`, `OPT-IO`, `PHY-SEC`, `LOG-SEC`, `SCHED`, `RQ-SIZE`.
-T or --tree	Displays the device information in a tree format. The default view of the output of the lsblk command is in tree format.
-V or --version	Displays version information.
-x `column` or --sort `column`	Sorts the output by a specific column.
-z or --zoned	Displays zoned storage model in the `ZONED` column. For zoned namespace (ZNS) Solid-State Drives (SSDs). For example, `none`, `host-aware`, `host-managed`.

Column headers

The -o parameter is followed by a list of columns that must be displayed in the output. The device information has the following column headings:

Table 2. Column headers
Column headers	Description
`NAME`	Specifies the device name.
`KNAME`	Specifies the internal kernel name of the device.
`MAJ:MIN`	Specifies the major or minor device number.
`FSTYPE`	Specifies the file system type.
`MOUNTPOINT`	Specifies the mount path.
`LABEL`	Specifies the file system label.
`UUID`	Specifies the file system Universally Unique Identifier (UUID).
`PARTLABEL`	Specifies the GUID Partition Table (GPT) partition label.
`PARTUUID`	Specifies the GPT partition UUID.
`SIZE`	Specifies the total capacity.
`RO`	Specifies whether the devices are read-only. If the value is 1, the device is read-only.
`RM`	Specifies whether the devices are removable. If the value is 1, the device is removable.
`MODEL`	Specifies the disk model name.
`SERIAL`	Specifies the serial number of the devices.
`STATE`	Specifies the state of the devices. For example, `running`, `suspended`.
`TYPE`	Specifies the type of the devices. For example, `disk`, `part`, `lvm`, `loop`, `rom`.
`ZONED`	Specifies the zone model of a device.
`TRAN`	Specifies the device transport type.
`SCHED`	Specifies the I/O scheduler name that is used for the device.

Examples

To list block devices in a tree structure, enter the following command:
```
lsblk
```
To list all the devices that include empty devices, enter the following command:
```
lsblk -a
```
To list only the base devices, enter the following command:
```
lsblk -d
```
To list file systems and mount points, enter the following command:
```
lsblk -f
```
To direct the output without any column headers to a JSON file, enter the following command:
```
lsblk -J -n
```
To display only the NAME, SIZE, TYPE, FSTYPE, and MOUNTPOINT columns, enter the following command:
```
lsblk -o NAME,SIZE,TYPE,FSTYPE,MOUNTPOINT
```
To display all the columns, enter the following command:
```
lsblk -O
```
To display the NAME, SIZE, and FSTYPE columns in a key=value pair, enter the following command:
```
lsblk -P -o NAME,SIZE,FSTYPE
```
To display the SSD TRIM support, enter the following command:
```
lsblk -D -o NAME,DISC-GRAN,DISC-MAX,DISC-ZERO
```
To sort disks by size in descending order and display the NAME, SIZE, and MODEL columns, enter the following command:
```
lsblk -d -x SIZE -o NAME,SIZE,MODEL
```
To display the device information in an inverted, dependency-based order, enter the following command:
```
lsblk -s
```