misc-utils/lsblk.8 - pub/scm/utils/util-linux/util-linux - Git at Google

 .TH LSBLK 8 "February 2013" "util-linux" "System Administration"
 .SH NAME
 lsblk \- list block devices
 .SH SYNOPSIS
 .B lsblk
 [options]
 .RI [ device ...]
 .SH DESCRIPTION
 .B lsblk
 lists information about all available or the specified block devices.  The
 .B lsblk
 command reads the
 .B sysfs
 filesystem and
 .B udev db
 to gather information. If the udev db is not available or lsblk is compiled without udev support than it
 tries to read LABELs, UUIDs and filesystem types from the block device. In this case root permissions
 are necessary.
 .PP
 The command prints all block devices (except RAM disks) in a tree-like format
 by default.  Use
 .B "lsblk \-\-help"
 to get a list of all available columns.
 .PP
 The default output, as well as the default output from options like
 .B \-\-fs
 and
 .BR \-\-topology ,
 is subject to change.  So whenever possible, you should avoid using default
 outputs in your scripts.  Always explicitly define expected columns by using
 .B \-\-output
 .I columns-list
 and
 .B \-\-list
 in environments where a stable output is required.
 .PP
 Note that
 .B lsblk
 might be executed in time when
 .B udev
 does not have all information about recently added or modified devices yet. In this
 case it is recommended to use
 .B "udevadm settle"
 before lsblk to synchronize with udev.
 .SH OPTIONS
 .TP
 .BR \-a , " \-\-all"
 Also list empty devices and RAM disk devices.
 .TP
 .BR \-b , " \-\-bytes"
 Print the SIZE column in bytes rather than in a human-readable format.
 .TP
 .BR \-D , " \-\-discard"
 Print information about the discarding capabilities (TRIM, UNMAP) for each device.
 .TP
 .BR \-d , " \-\-nodeps"
 Do not print holder devices or slaves.  For example, \fBlsblk \-\-nodeps /dev/sda\fR prints
 information about the sda device only.
 .TP
 .BR \-E , " \-\-dedup " \fIcolumn\fP
 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.

 The usual use case is to de-duplicate output on system multi-path devices, for
 example by \fB\-E WWN\fR.
 .TP
 .BR \-e , " \-\-exclude " \fIlist\fP
 Exclude the devices specified by the comma-separated \fIlist\fR of major device numbers.
 Note that RAM disks (major=1) are excluded by default if \fB\-\-all\fR is not specified.
 The filter is applied to the top-level devices only. This may be confusing for
 \fB\-\-list\fR output format where hierarchy of the devices is not obvious.
 .TP
 .BR \-f , " \-\-fs"
 Output info about filesystems.  This option is equivalent to
 .BR \-o\ NAME,FSTYPE,LABEL,UUID,FSAVAIL,FSUSE%,MOUNTPOINT .
 The authoritative information about filesystems and raids is provided by the
 .BR blkid (8)
 command.
 .TP
 .BR \-h , " \-\-help"
 Display help text and exit.
 .TP
 .BR \-I , " \-\-include " \fIlist\fP
 Include devices specified by the comma-separated \fIlist\fR of major device numbers.
 The filter is applied to the top-level devices only. This may be confusing for
 \fB\-\-list\fR output format where hierarchy of the devices is not obvious.
 .TP
 .BR \-i , " \-\-ascii"
 Use ASCII characters for tree formatting.
 .TP
 .BR \-J , " \-\-json"
 Use JSON output format.  It's strongly recommended to use \fB\-\-output\fR and
 also \fB\-\-tree\fR if necessary.
 .TP
 .BR \-l , " \-\-list"
 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.
 .TP
 .BR \-M , " \-\-merge"
 Group parents of sub-trees to provide more readable output for RAIDs and
 Multi-path devices. The tree-like output is required.
 .TP
 .BR \-m , " \-\-perms"
 Output info about device owner, group and mode.  This option is equivalent to
 .BR \-o\ NAME,SIZE,OWNER,GROUP,MODE .
 .TP
 .BR \-n , " \-\-noheadings"
 Do not print a header line.
 .TP
 .BR \-o , " \-\-output " \fIlist\fP
 Specify which output columns to print.  Use
 .B \-\-help
 to get a list of all supported columns.  The columns may affect tree-like output.
 The default is to use tree for the column 'NAME' (see also \fB\-\-tree\fR).

 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).
 .TP
 .BR \-O , " \-\-output\-all "
 Output all available columns.
 .TP
 .BR \-P , " \-\-pairs"
 Produce output in the form of key="value" pairs.
 All potentially unsafe characters are hex-escaped (\\x<code>).
 .TP
 .BR \-p , " \-\-paths"
 Print full device paths.
 .TP
 .BR \-r , " \-\-raw"
 Produce output in raw format.  All potentially unsafe characters are hex-escaped
 (\\x<code>) in the NAME, KNAME, LABEL, PARTLABEL and MOUNTPOINT columns.
 .TP
 .BR \-S , " \-\-scsi"
 Output info about SCSI devices only.  All partitions, slaves and holder devices are ignored.
 .TP
 .BR \-s , " \-\-inverse"
 Print dependencies in inverse order. If the \fB\-\-list\fR output is requested then
 the lines are still ordered by dependencies.
 .TP
 .BR \-T , " \-\-tree" [ =\fIcolumn ]
 Force tree-like output format.  If \fIcolumn\fP is specified, then a tree is printed in the column.
 The default is NAME column.
 .TP
 .BR \-t , " \-\-topology"
 Output info about block-device topology.
 This option is equivalent to
 .BR \-o\ NAME,ALIGNMENT,MIN-IO,OPT-IO,PHY-SEC,LOG-SEC,ROTA,SCHED,RQ-SIZE,RA,WSAME .
 .TP
 .BR \-V , " \-\-version"
 Display version information and exit.
 .TP
 .BR \-x , " \-\-sort " \fIcolumn\fP
 Sort output lines by \fIcolumn\fP. This option enables \fB\-\-list\fR output format by default.
 It is possible to use the option \fI\-\-tree\fP to force tree-like output and
 than the tree branches are sorted by the \fIcolumn\fP.
 .TP
 .BR \-z , " \-\-zoned"
 Print the zone model for each device.
 .TP
 .BR " \-\-sysroot " \fIdirectory\fP
 Gather data for a Linux instance other than the instance from which the lsblk
 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.

 .SH NOTES
 For partitions, some information (e.g., queue attributes) is inherited from the
 parent device.
 .PP
 The
 .B lsblk
 command needs to be able to look up each block device by major:minor numbers,
 which is done by using
 .IR /sys/dev/block .
 This sysfs block directory appeared in kernel 2.6.27 (October 2008).
 In case of problems with a new enough kernel, check that CONFIG_SYSFS
 was enabled at the time of the kernel build.

 .SH RETURN CODES
 .IP 0
 success
 .IP 1
 failure
 .IP 32
 none of specified devices found
 .IP 64
 some specified devices found, some not found

 .SH AUTHORS
 .nf
 Milan Broz <mbroz@redhat.com>
 Karel Zak <kzak@redhat.com>
 .fi
 .SH ENVIRONMENT
 .IP LSBLK_DEBUG=all
 enables lsblk debug output.
 .IP LIBBLKID_DEBUG=all
 enables libblkid debug output.
 .IP LIBMOUNT_DEBUG=all
 enables libmount debug output.
 .IP LIBSMARTCOLS_DEBUG=all
 enables libsmartcols debug output.
 .IP LIBSMARTCOLS_DEBUG_PADDING=on
 use visible padding characters. Requires enabled LIBSMARTCOLS_DEBUG.
 .SH SEE ALSO
 .BR ls (1),
 .BR blkid (8),
 .BR findmnt (8)
 .SH AVAILABILITY
 The lsblk command is part of the util-linux package and is available from
 https://www.kernel.org/pub/linux/utils/util-linux/.
	.TH LSBLK 8 "February 2013" "util-linux" "System Administration"
	.SH NAME
	lsblk \- list block devices
	.SH SYNOPSIS
	.B lsblk
	[options]
	.RI [ device ...]
	.SH DESCRIPTION
	.B lsblk
	lists information about all available or the specified block devices. The
	.B lsblk
	command reads the
	.B sysfs
	filesystem and
	.B udev db
	to gather information. If the udev db is not available or lsblk is compiled without udev support than it
	tries to read LABELs, UUIDs and filesystem types from the block device. In this case root permissions
	are necessary.
	.PP
	The command prints all block devices (except RAM disks) in a tree-like format
	by default. Use
	.B "lsblk \-\-help"
	to get a list of all available columns.
	.PP
	The default output, as well as the default output from options like
	.B \-\-fs
	and
	.BR \-\-topology ,
	is subject to change. So whenever possible, you should avoid using default
	outputs in your scripts. Always explicitly define expected columns by using
	.B \-\-output
	.I columns-list
	and
	.B \-\-list
	in environments where a stable output is required.
	.PP
	Note that
	.B lsblk
	might be executed in time when
	.B udev
	does not have all information about recently added or modified devices yet. In this
	case it is recommended to use
	.B "udevadm settle"
	before lsblk to synchronize with udev.
	.SH OPTIONS
	.TP
	.BR \-a , " \-\-all"
	Also list empty devices and RAM disk devices.
	.TP
	.BR \-b , " \-\-bytes"
	Print the SIZE column in bytes rather than in a human-readable format.
	.TP
	.BR \-D , " \-\-discard"
	Print information about the discarding capabilities (TRIM, UNMAP) for each device.
	.TP
	.BR \-d , " \-\-nodeps"
	Do not print holder devices or slaves. For example, \fBlsblk \-\-nodeps /dev/sda\fR prints
	information about the sda device only.
	.TP
	.BR \-E , " \-\-dedup " \fIcolumn\fP
	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.

	The usual use case is to de-duplicate output on system multi-path devices, for
	example by \fB\-E WWN\fR.
	.TP
	.BR \-e , " \-\-exclude " \fIlist\fP
	Exclude the devices specified by the comma-separated \fIlist\fR of major device numbers.
	Note that RAM disks (major=1) are excluded by default if \fB\-\-all\fR is not specified.
	The filter is applied to the top-level devices only. This may be confusing for
	\fB\-\-list\fR output format where hierarchy of the devices is not obvious.
	.TP
	.BR \-f , " \-\-fs"
	Output info about filesystems. This option is equivalent to
	.BR \-o\ NAME,FSTYPE,LABEL,UUID,FSAVAIL,FSUSE%,MOUNTPOINT .
	The authoritative information about filesystems and raids is provided by the
	.BR blkid (8)
	command.
	.TP
	.BR \-h , " \-\-help"
	Display help text and exit.
	.TP
	.BR \-I , " \-\-include " \fIlist\fP
	Include devices specified by the comma-separated \fIlist\fR of major device numbers.
	The filter is applied to the top-level devices only. This may be confusing for
	\fB\-\-list\fR output format where hierarchy of the devices is not obvious.
	.TP
	.BR \-i , " \-\-ascii"
	Use ASCII characters for tree formatting.
	.TP
	.BR \-J , " \-\-json"
	Use JSON output format. It's strongly recommended to use \fB\-\-output\fR and
	also \fB\-\-tree\fR if necessary.
	.TP
	.BR \-l , " \-\-list"
	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.
	.TP
	.BR \-M , " \-\-merge"
	Group parents of sub-trees to provide more readable output for RAIDs and
	Multi-path devices. The tree-like output is required.
	.TP
	.BR \-m , " \-\-perms"
	Output info about device owner, group and mode. This option is equivalent to
	.BR \-o\ NAME,SIZE,OWNER,GROUP,MODE .
	.TP
	.BR \-n , " \-\-noheadings"
	Do not print a header line.
	.TP
	.BR \-o , " \-\-output " \fIlist\fP
	Specify which output columns to print. Use
	.B \-\-help
	to get a list of all supported columns. The columns may affect tree-like output.
	The default is to use tree for the column 'NAME' (see also \fB\-\-tree\fR).

	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).
	.TP
	.BR \-O , " \-\-output\-all "
	Output all available columns.
	.TP
	.BR \-P , " \-\-pairs"
	Produce output in the form of key="value" pairs.
	All potentially unsafe characters are hex-escaped (\\x<code>).
	.TP
	.BR \-p , " \-\-paths"
	Print full device paths.
	.TP
	.BR \-r , " \-\-raw"
	Produce output in raw format. All potentially unsafe characters are hex-escaped
	(\\x<code>) in the NAME, KNAME, LABEL, PARTLABEL and MOUNTPOINT columns.
	.TP
	.BR \-S , " \-\-scsi"
	Output info about SCSI devices only. All partitions, slaves and holder devices are ignored.
	.TP
	.BR \-s , " \-\-inverse"
	Print dependencies in inverse order. If the \fB\-\-list\fR output is requested then
	the lines are still ordered by dependencies.
	.TP
	.BR \-T , " \-\-tree" [ =\fIcolumn ]
	Force tree-like output format. If \fIcolumn\fP is specified, then a tree is printed in the column.
	The default is NAME column.
	.TP
	.BR \-t , " \-\-topology"
	Output info about block-device topology.
	This option is equivalent to
	.BR \-o\ NAME,ALIGNMENT,MIN-IO,OPT-IO,PHY-SEC,LOG-SEC,ROTA,SCHED,RQ-SIZE,RA,WSAME .
	.TP
	.BR \-V , " \-\-version"
	Display version information and exit.
	.TP
	.BR \-x , " \-\-sort " \fIcolumn\fP
	Sort output lines by \fIcolumn\fP. This option enables \fB\-\-list\fR output format by default.
	It is possible to use the option \fI\-\-tree\fP to force tree-like output and
	than the tree branches are sorted by the \fIcolumn\fP.
	.TP
	.BR \-z , " \-\-zoned"
	Print the zone model for each device.
	.TP
	.BR " \-\-sysroot " \fIdirectory\fP
	Gather data for a Linux instance other than the instance from which the lsblk
	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.

	.SH NOTES
	For partitions, some information (e.g., queue attributes) is inherited from the
	parent device.
	.PP
	The
	.B lsblk
	command needs to be able to look up each block device by major:minor numbers,
	which is done by using
	.IR /sys/dev/block .
	This sysfs block directory appeared in kernel 2.6.27 (October 2008).
	In case of problems with a new enough kernel, check that CONFIG_SYSFS
	was enabled at the time of the kernel build.

	.SH RETURN CODES
	.IP 0
	success
	.IP 1
	failure
	.IP 32
	none of specified devices found
	.IP 64
	some specified devices found, some not found

	.SH AUTHORS
	.nf
	Milan Broz <mbroz@redhat.com>
	Karel Zak <kzak@redhat.com>
	.fi
	.SH ENVIRONMENT
	.IP LSBLK_DEBUG=all
	enables lsblk debug output.
	.IP LIBBLKID_DEBUG=all
	enables libblkid debug output.
	.IP LIBMOUNT_DEBUG=all
	enables libmount debug output.
	.IP LIBSMARTCOLS_DEBUG=all
	enables libsmartcols debug output.
	.IP LIBSMARTCOLS_DEBUG_PADDING=on
	use visible padding characters. Requires enabled LIBSMARTCOLS_DEBUG.
	.SH SEE ALSO
	.BR ls (1),
	.BR blkid (8),
	.BR findmnt (8)
	.SH AVAILABILITY
	The lsblk command is part of the util-linux package and is available from
	https://www.kernel.org/pub/linux/utils/util-linux/.