-.\" -*- nroff -*-
.TH LSBLK 8 "February 2013" "util-linux" "System Administration"
.SH NAME
lsblk \- list block devices
.SH SYNOPSIS
.B lsblk
-.RB [ options ]
+[options]
.RI [ device ...]
.SH DESCRIPTION
.B lsblk
.B sysfs
filesystem and
.B udev db
-to gather information.
+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
to get a list of all available columns.
.PP
The default output, as well as the default output from options like
-.BR \-\-fs
+.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
.SH OPTIONS
.TP
.BR \-a , " \-\-all"
-Also list empty devices. (By default they are skipped.)
+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.
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. The filter is applied to the
-top-level devices only.
+Note that RAM disks (major=1) are excluded by default if \fB\-\-all\fR is no specified.
+The filter is applied to the top-level devices only. This maybe 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,MOUNTPOINT .
+.BR -o\ NAME,FSTYPE,LABEL,UUID,MOUNTPOINT .
The authoritative information about filesystems and raids is provided by the
.BR blkid (8)
command.
.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.
+The filter is applied to the top-level devices only. This maybe 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.
+.TP
.BR \-l , " \-\-list"
-Produce output in the form of a 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
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 "
+.BR \-O , " \-\-output\-all "
Output all available columns.
.TP
.BR \-P , " \-\-pairs"
Output info about SCSI devices only. All partitions, slaves and holder devices are ignored.
.TP
.BR \-s , " \-\-inverse"
-Print dependencies in inverse order.
+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,WSAME .
+.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 output \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. This option is designed for the testing purpose.
+
.SH NOTES
For partitions, some information (e.g. queue attributes) is inherited from the
parent device.
.B lsblk
command needs to be able to look up each block device by major:minor numbers,
which is done by using
-.BR /sys/dev/block .
+.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 findmnt (8),
+.BR ls (1),
.BR blkid (8),
-.BR ls (1)
+.BR findmnt (8)
.SH AVAILABILITY
The lsblk command is part of the util-linux package and is available from
-ftp://ftp.kernel.org/pub/linux/utils/util-linux/.
+https://www.kernel.org/pub/linux/utils/util-linux/.
projects / thirdparty / util-linux.git / blobdiff