In AIX we don't tend to use
single-user mode very much, because many problems require having the rootvg
unmounted for repairs. However, if there is a problem with a filesystem or
volume group *and* the system boots fine from the rootvg, then booting into
single-user to repair or perform work has advantages:
- It boots quicker than
Maintenance Mode.
- You can boot off the normal
system rootvg without finding AIX Install media or setting up a NIM
SPOT.
- It allows you to run all
commands you would normally have access to in multiuser.
PROCEDURE:
1. Boot system with no media in the CD/DVD drive
2. Wait until you see the options of choosing another boot list, and hear
beeps on the console
3. Press 6 to start diagnostics
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IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM
1 = SMS Menu 5 = Default Boot List
8 = Open Firmware Prompt 6 = Stored Boot List
Memory Keyboard Network SCSI Speaker
You will see the normal AIX boot header, since you are booting from your
system hard disk:
-------------------------------------------------------------------------------
Welcome to AIX.
boot
image timestamp: 08:55 07/25
The current time and date:
10:01:01 07/25/2009
number of processors: 1
size of memory: 512MB
boot device:
/vdevice/v-scsi@30000003/disk@8700000000000000
kernel size:
15004862; 64 bit kernel
-------------------------------------------------------------------------------
DIAGNOSTIC
OPERATING INSTRUCTIONS
At this point the dianostic license information comes up. At the end it
says:
Several keys are
used to control the diagnostics:
- The Enter key continues
the procedure or performs an action.
- The Backspace
key allows keying errors to be corrected.
- The cursor keys
are used to select an option.
To continue, press
Enter.
The next screen will show you Diagnostic Functions you can perform.
On newer versions of firmware you will see Option 5 to start Single User
Mode.
On older firmware you will have to go to:
3. Task selection
and scroll way down and select 'start shell'.
FUNCTION SELECTION
1. Diagnostic
Routines
This
selection will test the machine hardware. Wrap plugs and
other advanced functions will not be used.
2. Advanced
Diagnostic Routines
This
selection will test the machine hardware. Wrap plugs and
other advanced functions will be used.
3. Task
Selection(Diagnostics, Advanced Diagnostics, Service Aids, etc.)
This
selection will list the tasks supported by these procedures.
Once
a task is selected, a resource menu may be presented showing
all
resources supported by the task.
4. Resource
Selection
This
selection will list the resources in the system that are supported
by
the diagnostic programs. Once a resource is selected, a task menu will
be
presented showing all tasks that can be run on the resource(s).
5. Single User
Mode
The
system will enter single-user mode for software maintenance.
To make a
selection, type the number and press Enter [1]: 5
The system will
now continue the boot process. Please wait...
Saving Base
Customize Data to boot disk
Starting the sync
daemon
Starting the error
daemon
System
initialization completed.
INIT: SINGLE-USER
MODE
Password:
Give the root password at the "Password" prompt.
After getting logged in you will see a minimal rootvg mounted:
# df
Filesystem
512-blocks Free %Used Iused %Iused
Mounted on
/dev/hd4
131072 70696 47%
2127 21% /
/dev/hd2
2129920 102104 96%
33435 71% /usr
/dev/hd9var
196608 136080 31% 431
3% /var
/dev/hd3
98304 74904 24%
148 2% /tmp
And not very many processes running:
# ps -ef
UID PID PPID C STIME
TTY TIME CMD
root
1 0 0 09:49:40
- 0:00 /etc/init s
root
151630 1 0 09:49:51 vty0 0:00 -ksh
root
168040 1 0 09:49:48 - 0:00
/usr/sbin/syncd 60
root
172160 151630 2 09:51:58 vty0 0:00 ps -ef
root
176222 1 0 09:49:51 -
0:00 /usr/lib/errdemon
RUNNING 64-BIT COMMANDS
Some commands such as fsck may give you an error that 64-bit applications
have not been enabled.
This is because this is enabled from inittab:
# grep 64
/etc/inittab
load64bit:2:wait:/etc/methods/cfg64
>/dev/console 2>&1 # Enable 64-bit execs
so run it by hand:
#
/etc/methods/cfg64
EXITING SINGLE-USER MODE
To exit single-user mode and boot into multiuser in RunLevel 2 use:
# telinit 2
INIT: New run
level: 2
Setting tunable
parameters...complete
Starting
Multi-user Initialization
Performing
auto-varyon of Volume Groups
Activating
all paging spaces
swapon: Paging
device /dev/paging00 is already active.
swapon: Paging
device /dev/hd6 activated.
The current volume
is: /dev/hd10opt
Primary superblock
is valid.
Performing
all automatic mounts
mount: /dev/hd4 on
/: Device busy
Multi-user
initialization completed
Checking for
srcmstr active...complete
Starting tcpip
daemons:
0513-059 The
syslogd Subsystem has been started. Subsystem PID is 139390.
Jul 25 09:53:21
puma syslog:err|error syslogd: /tmp/syslog.debug: errno = 2
0513-059 The
sendmail Subsystem has been started. Subsystem PID is 217218.
0513-059 The
portmap Subsystem has been started. Subsystem PID is 94364.
0513-059 The inetd
Subsystem has been started. Subsystem PID is 233600.
0513-059 The xntpd
Subsystem has been started. Subsystem PID is 254104.
0513-059 The snmpd
Subsystem has been started. Subsystem PID is 241836.
0513-059 The
hostmibd Subsystem has been started. Subsystem PID is 237710.
0513-059 The
snmpmibd Subsystem has been started. Subsystem PID is 180328.
0513-059 The
aixmibd Subsystem has been started. Subsystem PID is 262282.
Finished starting
tcpip daemons.
0513-059 The
muxatmd Subsystem has been started. Subsystem PID is 127156.
Starting NFS
services:
0513-059 The biod
Subsystem has been started. Subsystem PID is 229540.
0513-059 The
rpc.statd Subsystem has been started. Subsystem PID is 286868.
0513-059 The
rpc.lockd Subsystem has been started. Subsystem PID is 299180.
Completed NFS
services.
0513-059 The ctrmc
Subsystem has been started. Subsystem PID is 290968.
Unauthorized use
of this system is prohibited.
login:
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