.\" SPDX-License-Identifier: BSD-2-Clause
.\"
.\" Proposed manual page source for FreeBSD lsblk(8).
.\"
.Dd January 17, 2026
.Dt LSBLK 8
.Os
.Sh NAME
.Nm lsblk
.Nd list block devices and their device trees
.Sh SYNOPSIS
.Nm
.Op Ar disk
.Nm
.Fl d
.Nm
.Fl -disks
.Nm
.Fl -version
.Nm
.Fl -help
.Sh DESCRIPTION
The
.Nm
utility prints a tree-oriented view of block devices present in the system.
The output is intended to provide a compact summary of whole disks, partition
schemes, partitions, and related providers (for example, encryption layers),
including size and basic identification.
.Pp
If the optional
.Ar disk
operand is specified, only the device tree rooted at that disk-like device is
displayed (for example,
.Cm ada0
or
.Cm da1 ) .
.Pp
The default output format is columnar.
Typical columns include:
.Bl -tag -width "MAJ:MIN" -compact
.It Cm DEVICE
Device or provider name.
.It Cm MAJ:MIN
Device numbers, formatted as major:minor when available.
.It Cm SIZE
Size of the device or provider.
.It Cm TYPE
Provider type or partition type (for example,
.Cm GPT ,
.Cm MBR ,
.Cm freebsd-ufs ,
.Cm freebsd-zfs ) .
.It Cm LABEL
Label associated with the provider when available.
.It Cm MOUNT
Mount point when available; certain types may display a sentinel such as
.Ql <ZFS>
to indicate managed mounts.
.El
.Sh OPTIONS
.Bl -tag -width "--version" -offset indent
.It Fl d , Fl -disks
Display only whole disks (no partition/provider tree expansion).
This mode is commonly used to summarize inventory and model information.
.It Fl -help
Display a brief usage message and exit.
.It Fl -version
Display version information and exit.
.El
.Sh EXIT STATUS
.Ex -std
.Sh EXAMPLES
List all block devices in the system:
.Bd -literal -offset indent
# lsblk
DEVICE MAJ:MIN SIZE TYPE LABEL MOUNT
ada0 0:92 932G GPT - -
ada0p1 0:100 200M efi efiboot0 -
ada0p2 0:101 512K freebsd-boot gptboot0 -
<FREE> -:- 492K - - -
ada0p3 0:102 931G freebsd-zfs zfs0 <ZFS>
ada0p3.eli 0:106 931G freebsd-zfs - <ZFS>
.Ed
.Pp
List only the
.Cm da1
device tree:
.Bd -literal -offset indent
# lsblk da1
DEVICE MAJ:MIN SIZE TYPE LABEL MOUNT
da1 0:80 2.0G MBR - -
da1s1 0:80 2.0G freebsd - -
da1s1a 0:81 1.0G freebsd-ufs root /
da1s1b 0:82 1.0G freebsd-swap swap SWAP
.Ed
.Pp
List whole disks only:
.Bd -literal -offset indent
# lsblk -d
DEVICE SIZE MODEL
ada0 1.8T Samsung SSD 860 QVO 2TB
ada1 119G SAMSUNG SSD PM830 mSATA 128GB
- 2T TOTAL SYSTEM STORAGE
.Ed
.Pp
Display version information:
.Bd -literal -offset indent
# lsblk --version
.Ed
.Pp
Restrict output to a disk, while still using disk-only mode (useful on systems
with many devices):
.Bd -literal -offset indent
# lsblk -d ada0
.Ed
.Pp
Enumerate physical disks as seen by the kernel (useful for establishing the set
of disk roots prior to invoking
.Nm ) :
.Bd -literal -offset indent
# sysctl kern.disks
kern.disks: ada0 da0 da1
.Ed
.Pp
List memory-backed disks (for example,
.Xr md 4
devices) and then display each device tree:
.Bd -literal -offset indent
# mdconfig -l
md0
# lsblk md0
.Ed
.Pp
Produce a compact report by combining whole-disk output with standard text tools:
.Bd -literal -offset indent
# lsblk -d | awk 'NR==1 || $1 ~ /^ada/ { print }'
.Ed
.Sh SEE ALSO
.Xr sysctl 8 ,
.Xr mdconfig 8 ,
.Xr gpart 8 ,
.Xr geom 8 ,
.Xr geli 8 ,
.Xr zfs 8 ,
.Xr zpool 8
.Sh STANDARDS
The
.Nm
utility is not specified by any standard.
.Sh AUTHORS
This manual page is a proposed reference for a FreeBSD
.Nm
implementation.
.Sh BUGS
Column availability and the meaning of certain sentinel values depend on the
underlying device types and system configuration.
