You boot a system to a single-user state for the purpose of performing system maintenance, such as backing up a file system or to troubleshoot other system issues.
See Using Your Assigned Administrative Rights in Securing Users and Processes in Oracle Solaris 11.2 .
# init 0
ok boot -s
SINGLE USER MODE Root password for system maintenance (control-d to bypass): xxxxxx
# reboot -p
Because the Fast Reboot feature is enabled by default, you must specify the –p option when rebooting the system, which enables the GRUB menu to be displayed at boot time. To disable the Fast Reboot feature so that the –p option does not need to be specified, see Changing the Default Fast Reboot Behavior.
See Adding Kernel Arguments by Editing the GRUB Menu at Boot Time for more information about editing the GRUB menu at boot time.
# who -r
The following example shows the messages from booting a SPARC based system to run level S after the boot process has started.
# init 0
# svc.startd: The system is coming down. Please wait.
svc.startd: 122 system services are now being stopped.
Mar 5 10:30:33 system1 syslogd: going down on signal 15
svc.startd: Killing user processes.
umount: /ws busy
umount: /home busy
Mar 5 17:30:50 The system is down. Shutdown took 70 seconds.
syncing file systems... done
Program terminated
{1c} ok boot -s
SC Alert: Host System has Reset
NOV 17 21:46:59 ERROR: System memory downgraded to 2-channel mode from 4-channel mode
NOV 17 21:47:00 ERROR: Available system memory is less than physically installed memory
NOV 17 21:47:00 ERROR: System DRAM Available: 008192 MB Physical: 016384 MB
Sun Fire T200, No Keyboard
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Ethernet address 0:14:4f:1d:e8:da, Host ID: 841de8da.
ERROR: The following devices are disabled:
MB/CMP0/CH2/R0/D0
Boot device: /pci@7c0/pci@0/pci@1/pci@0,2/LSILogic,sas@2/disk@0,0:a
File and args: -s
SunOS Release 5.11 Version 11.2 64-bit
Copyright (c) 1983, 2014, Oracle and/or its affiliates. All rights reserved.
NOTICE: Hypervisor does not support CPU power management
Booting to milestone "milestone/single-user:default".
Hostname: system1
Requesting System Maintenance Mode
SINGLE USER MODE
Enter root password (control-d to bypass): xxxxxx
single-user privilege assigned to root on /dev/console.
Entering System Maintenance Mode
Mar 5 10:36:14 su: 'su root' succeeded for root on /dev/console
Oracle Corporation SunOS 5.11 11.2 July 2014
root@system1:~# who -r
run-level S Mar 5 10:35 S 0 0
root@tsystem1:~#
Example 4-15 x86: Booting a System to a Single-User State (Run Level S)The following example shows the messages from booting an x86 based system to run level S after the boot process has started.
root@system-04:~# init 0
root@system-04:~# svc.startd: The system is coming down. Please wait.
svc.startd: 129 system services are now being stopped.
Apr 23 13:51:28 system-04 syslogd: going down on signal 15
svc.startd: Killing user processes.
umount: /home busy
Apr 23 13:51:36 The system is down. Shutdown took 26 seconds.
syncing file systems... done
Press any key to reboot.
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.LSI Corporation MPT SAS BIOS
MPTBIOS-6.26.00.00 (2008.10.14)
Copyright 2000-2008 LSI Corporation.
Initializing..|Press F2 to runS POPUP (CTRL+P on Remote Keyboard)
Press F12 to boot from the network (CTRL+N on Remote Keyboard)
System Memory : 8.0 GB , Inc.
Auto-Detecting Pri Master..ATAPI CDROM 0078
Ultra DMA Mode-2
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GNU GRUB version 1.99,5.11.0.175.1.0.0.14.0
****************************************************************************
*Oracle Solaris 11.2 *
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
****************************************************************************
Use the * and * keys to select which entry is highlighted.
Press enter to boot the selected OS, 'e' to edit the commands
before booting or 'c' for a command-line.
GNU GRUB version 1.99,5.11.0.175.1.0.0.14.0
****************************************************************************
* setparams 'Oracle Solaris 11.2' *
* *
* insmod part_msdos *
* insmod part_sunpc *
* insmod part_gpt *
* insmod zfs *
* search --no-floppy --fs-uuid --set=root cd03199c4187a7d7 *
* zfs-bootfs /ROOT/s11u2/@/ zfs_bootfs *
* set kern=/platform/i86pc/kernel/amd64/unix *
* echo -n "Loading ${root}/ROOT/s11u2 /@$kern: " *
* $multiboot /ROOT/s11u2/@/$kern $kern -B $zfs_bootfs -s
* set gfxpayload="1024x768x32;1024x768x16;800x600x16;640x480x16;640x480x1\ *
* 5;640x480x32" **
****************************************************************************
Minimum Emacs-like screen editing is supported. TAB lists
completions. Press Ctrl-x or F10 to boot, Ctrl-c or F2 for
a command-line or ESC to discard edits and return to the GRUB menu.
Booting a command list
Loading hd0,msdos1,sunpc1/ROOT/s11u2/@/platform/i86pc/kernel/amd64/unix: 0
%...done.
Loading hd0,msdos1,sunpc1/ROOT/s11u2/@/platform/i86pc/amd64/boot_archive:
0%...
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SunOS Release 5.11 Version 11.2 64-bit
Copyright (c) 1983, 2014, Oracle and/or its affiliates. All rights reserved.
NOTICE: kmem_io_2G arena created
Booting to milestone "milestone/single-user:default".
Hostname: system-04
Requesting System Maintenance Mode
SINGLE USER MODE
Enter user name for system maintenance (control-d to bypass): root
Enter root password (control-d to bypass): xxxxxxx
single-user privilege assigned to root on /dev/console.
Entering System Maintenance Mode
May 8 11:13:44 su: 'su root' succeeded for root on /dev/console
Oracle Corporation SunOS 5.11 11.2 July 2014
You have new mail.
root@system-04:~# who -r
. run-level S Apr 23 14:49 S 0 0