REBOOT(8) Maintenance Procedures REBOOT(8)


reboot - restart the operating system


/usr/sbin/reboot [-dlnq] [boot_arguments]

/usr/sbin/reboot [-f [-e environment] | -p] [-dlnq] [boot_arguments]


The reboot utility restarts the kernel. The kernel is loaded into memory
by the PROM monitor, which transfers control to the loaded kernel.

On x86 systems, when the -f flag is specified, the running kernel will
load the next kernel into memory, then transfer control to the newly
loaded kernel. This form of reboot is shown in the second synopsis,

Although reboot can be run by the super-user at any time, shutdown(8) is
normally used first to warn all users logged in of the impending loss of
service. See shutdown(8) for details.

The reboot utility performs a sync(8) operation on the disks, and then a
multi-user reboot is initiated. See init(8) for details. On x86 systems,
reboot may also update the boot archive as needed to ensure a successful

The reboot utility normally logs the reboot to the system log daemon,
syslogd(8), and places a shutdown record in the login accounting file
/var/adm/wtmpx. These actions are inhibited if the -n or -q options are

Normally, the system reboots itself at power-up or after crashes.


The following options are supported:


Force a system crash dump before rebooting. See dumpadm(8) for
information on configuring system crash dumps.


If -f is present, reboot to the specified boot environment.


Fast reboot, bypassing firmware and boot loader. The new kernel will
be loaded into memory by the running kernel, and control will be
transferred to the newly loaded kernel. If disk or kernel arguments
are specified, they must be specified before other boot arguments.

This option is currently available only on x86 systems.

Service svc:/system/boot-config:default is enabled by default. It
requires solaris.system.shutdown as action_authorization and
value_authorization. When the config/fastreboot_default property is
set to true, reboot will behave as reboot -f. The value of this
property can be changed using svccfg(8) and svcadm(8), to control the
default reboot behavior.

See EXAMPLES for details.


Suppress sending a message to the system log daemon, syslogd(8) about
who executed reboot.


Avoid calling sync(2) and do not log the reboot to syslogd(8) or to
/var/adm/wtmpx. The kernel still attempts to sync filesystems prior
to reboot, except if the -d option is also present. If -d is used
with -n, the kernel does not attempt to sync file systems.


Reboot to prom. This flag can be used to reboot the system through
firmware without changing the default reboot behavior as denoted by
the config/fastreboot_default property setting in system/boot-config

This option is currently available only on x86 systems. The -p and -f
options are mutually exclusive.


Quick. Reboot quickly and ungracefully, without shutting down running
processes first.


The following operands are supported:


An optional boot_arguments specifies arguments to the uadmin(2)
function that are passed to the boot program and kernel upon restart.
The form and list of arguments is described in the boot(8) and
kernel(8) man pages. If the arguments are specified, whitespace
between them is replaced by single spaces unless the whitespace is
quoted for the shell. If the boot_arguments begin with a hyphen, they
must be preceded by the -- delimiter (two hyphens) to denote the end
of the reboot argument list.


Example 1: Passing the -r and -v Arguments to boot

In the following example, the delimiter -- (two hyphens) must be used to
separate the options of reboot from the arguments of boot(8).

example# reboot -dl -- -rv

Example 2: Rebooting Using a Specific Disk and Kernel

The following example reboots using a specific disk and kernel.

example# reboot disk1 kernel.test/unix

Example 3: Fast Rebooting

The following examples use the -f option to perform fast reboots.

If service svc:/system/boot-config:default is enabled and property
config/fastreboot_default is set to true, the -f option can be omitted.

The following command reboots to the default entry in the boot menu file

example# reboot -f

The following command reboots to another UFS root disk.

example# reboot -f -- '/dev/dsk/c1d0s0'

The following command reboots to another ZFS root pool.

example# reboot -f -- 'rpool/ROOT/root2'

The following command reboots to mykernel on the same disk with -k

example# reboot -f -- '/platform/i86pc/mykernel/amd64/unix -k'

The following command reboots to mykernel off another root disk mounted
on /mnt.

example# reboot -f -- '/mnt/platform/i86pc/mykernel/amd64/unix -k'

The following command reboots to /platform/i86pc/kernel/$ISADIR/unix on
another boot environment named second_root.

example# reboot -f -e second_root

The following command reboots to the same kernel with -kv options.

example# reboot -f -- '-kv'

The following commands disable the fast-reboot-by-default behavior.

example# svccfg -s "system/boot-config:default" \
setprop config/fastreboot_default=false
example# svcadm refresh svc:/system/boot-config:default

The following commands re-enable the fast-reboot-by-default behavior.

example# svccfg -s "system/boot-config:default" \
setprop config/fastreboot_default=true
example# svcadm refresh svc:/system/boot-config:default

Example 4: Rebooting to a Particular Boot Menu Entry

The following commands will reboot to entry 2 in the boot menu.

example# bootadm list-menu
the location for the active menu is: /rpool/boot/menu.lst
Index Default Dataset Menu
0 - rpool/ROOT/test-182 test-182
1 * rpool/ROOT/test-183 test-183
2 - rpool/ROOT/test-183 test-183
example# reboot 2



login accounting file


mdb(1), sync(2), uadmin(2), reboot(3C), attributes(7), boot(8),
dumpadm(8), fsck(8), halt(8), init(8), kernel(8), shutdown(8), svcadm(8),
svccfg(8), sync(8), syslogd(8)


The reboot utility does not execute the scripts in /etc/rcnum.d or
execute shutdown actions in inittab(5). To ensure a complete shutdown of
system services, use shutdown(8) or init(8) to reboot a Solaris system.

August 29, 2021 REBOOT(8)