\fBlsblk\fP lists information about all available or the specified block devices. The \fBlsblk\fP command reads the \fBsysfs\fP filesystem and \fBudev db\fP to gather information. If the udev db is not available or \fBlsblk\fP is compiled without udev support, then it tries to read LABELs, UUIDs and filesystem types from the block device. In this case root permissions are necessary.
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The command prints all block devices (except RAM disks) in a tree\-like format by default. Use \fBlsblk \-\-help\fP to get a list of all available columns.
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The default output, as well as the default output from options like \fB\-\-fs\fP and \fB\-\-topology\fP, is subject to change. So whenever possible, you should avoid using default outputs in your scripts. Always explicitly define expected columns by using \fB\-\-output\fP\fIcolumns\-list\fP and \fB\-\-list\fP in environments where a stable output is required.
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Note that \fBlsblk\fP might be executed in time when \fBudev\fP does not have all information about recently added or modified devices yet. In this case it is recommended to use \fBudevadm settle\fP before \fBlsblk\fP to synchronize with udev.
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The relationship between block devices and filesystems is not always one\-to\-one. The filesystem may use more block devices, or the same filesystem may be accessible by more paths. This is the reason why \fBlsblk\fP provides MOUNTPOINT and MOUNTPOINTS (pl.) columns. The column MOUNTPOINT displays only one mount point (usually the last mounted instance of the filesystem), and the column MOUNTPOINTS displays by multi\-line cell all mount points associated with the device.
.SH"OPTIONS"
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\fB\-A\fP, \fB\-\-noempty\fP
.RS4
Don\(cqt print empty devices.
.RE
.sp
\fB\-a\fP, \fB\-\-all\fP
.RS4
Disable all built\-in filters and list all empty devices and RAM disk devices too.
.RE
.sp
\fB\-b\fP, \fB\-\-bytes\fP
.RS4
Print the sizes in bytes rather than in a human\-readable format.
.sp
By default, the unit, sizes are expressed in, is byte, and unit prefixes are in
power of 2^10 (1024). Abbreviations of symbols are exhibited truncated in order
to reach a better readability, by exhibiting alone the first letter of them;
examples: "1 KiB" and "1 MiB" are respectively exhibited as "1 K" and "1 M",
then omitting on purpose the mention "iB", which is part of these abbreviations.
Do not print holder devices or slaves. For example, \fBlsblk \-\-nodeps /dev/sda\fP prints information about the sda device only.
.RE
.sp
\fB\-E\fP, \fB\-\-dedup\fP\fIcolumn\fP
.RS4
Use \fIcolumn\fP as a de\-duplication key to de\-duplicate output tree. If the key is not available for the device, or the device is a partition and parental whole\-disk device provides the same key than the device is always printed.
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The usual use case is to de\-duplicate output on system multi\-path devices, for example by \fB\-E WWN\fP.
.RE
.sp
\fB\-e\fP, \fB\-\-exclude\fP\fIlist\fP
.RS4
Exclude the devices specified by the comma\-separated \fIlist\fP of major device numbers. Note that RAM disks (major=1) are excluded by default if \fB\-\-all\fP is not specified. The filter is applied to the top\-level devices only. This may be confusing for \fB\-\-list\fP output format where hierarchy of the devices is not obvious.
.RE
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\fB\-f\fP, \fB\-\-fs\fP
.RS4
Output info about filesystems. This option is equivalent to \fB\-o NAME,FSTYPE,FSVER,LABEL,UUID,FSAVAIL,FSUSE%,MOUNTPOINTS\fP. The authoritative information about filesystems and raids is provided by the \fBblkid\fP(8) command.
.RE
.sp
\fB\-I\fP, \fB\-\-include\fP\fIlist\fP
.RS4
Include devices specified by the comma\-separated \fIlist\fP of major device numbers. The filter is applied to the top\-level devices only. This may be confusing for \fB\-\-list\fP output format where hierarchy of the devices is not obvious.
Use JSON output format. It\(cqs strongly recommended to use \fB\-\-output\fP and also \fB\-\-tree\fP if necessary.
.RE
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\fB\-l\fP, \fB\-\-list\fP
.RS4
Produce output in the form of a list. The output does not provide information about relationships between devices and since version 2.34 every device is printed only once if \fB\-\-pairs\fP or \fB\-\-raw\fP not specified (the parsable outputs are maintained in backwardly compatible way).
.RE
.sp
\fB\-M\fP, \fB\-\-merge\fP
.RS4
Group parents of sub\-trees to provide more readable output for RAIDs and Multi\-path devices. The tree\-like output is required.
.RE
.sp
\fB\-m\fP, \fB\-\-perms\fP
.RS4
Output info about device owner, group and mode. This option is equivalent to \fB\-o NAME,SIZE,OWNER,GROUP,MODE\fP.
Specify which output columns to print. Use \fB\-\-help\fP to get a list of all supported columns. The columns may affect tree\-like output. The default is to use tree for the column \(aqNAME\(aq (see also \fB\-\-tree\fP).
.sp
The default list of columns may be extended if \fIlist\fP is specified in the format \fI+list\fP (e.g., \fBlsblk \-o +UUID\fP).
Produce output in the form of key="value" pairs. The output lines are still ordered by dependencies. All potentially unsafe value characters are hex\-escaped (\(rsx<code>). See also option \fB\-\-shell\fP.
Produce output in raw format. The output lines are still ordered by dependencies. All potentially unsafe characters are hex\-escaped (\(rsx<code>) in the NAME, KNAME, LABEL, PARTLABEL and MOUNTPOINT columns.
.RE
.sp
\fB\-S\fP, \fB\-\-scsi\fP
.RS4
Output info about SCSI devices only. All partitions, slaves and holder devices are ignored.
.RE
.sp
\fB\-s\fP, \fB\-\-inverse\fP
.RS4
Print dependencies in inverse order. If the \fB\-\-list\fP output is requested then the lines are still ordered by dependencies.
.RE
.sp
\fB\-T\fP, \fB\-\-tree\fP[\fB=\fP\fIcolumn\fP]
.RS4
Force tree\-like output format. If \fIcolumn\fP is specified, then a tree is printed in the column. The default is NAME column.
.RE
.sp
\fB\-t\fP, \fB\-\-topology\fP
.RS4
Output info about block\-device topology. This option is equivalent to
Specifies output width as a number of characters. The default is the number of the terminal columns, and if not executed on a terminal, then output width is not restricted at all by default. This option also forces \fBlsblk\fP to assume that terminal control characters and unsafe characters are not allowed. The expected use\-case is for example when \fBlsblk\fP is used by the \fBwatch\fP(1) command.
.RE
.sp
\fB\-x\fP, \fB\-\-sort\fP\fIcolumn\fP
.RS4
Sort output lines by \fIcolumn\fP. This option enables \fB\-\-list\fP output format by default. It is possible to use the option \fB\-\-tree\fP to force tree\-like output and than the tree branches are sorted by the \fIcolumn\fP.
.RE
.sp
\fB\-y\fP, \fB\-\-shell\fP
.RS4
The column name will be modified to contain only characters allowed for shell variable identifiers, for example, MIN_IO and FSUSE_PCT instead of MIN\-IO and FSUSE%. This is usable, for example, with \fB\-\-pairs\fP. Note that this feature has been automatically enabled for \fB\-\-pairs\fP in version 2.37, but due to compatibility issues, now it\(cqs necessary to request this behavior by \fB\-\-shell\fP.
.RE
.sp
\fB\-z\fP, \fB\-\-zoned\fP
.RS4
Print the zone related information for each device.
.RE
.sp
\fB\-\-sysroot\fP\fIdirectory\fP
.RS4
Gather data for a Linux instance other than the instance from which the \fBlsblk\fP command is issued. The specified directory is the system root of the Linux instance to be inspected. The real device nodes in the target directory can be replaced by text files with udev attributes.
For partitions, some information (e.g., queue attributes) is inherited from the parent device.
.sp
The \fBlsblk\fP command needs to be able to look up each block device by major:minor numbers, which is done by using \fI/sys/dev/block\fP. This sysfs block directory appeared in kernel 2.6.27 (October 2008). In case of problems with a new enough kernel, check that \fBCONFIG_SYSFS\fP was enabled at the time of the kernel build.
