To make the processor online/offline:

# psrinfo
- Displays information about processors

Output:
bash-3.00# psrinfo
0 on-line since 08/18/2009 12:43:45
1 on-line since 08/18/2009 12:43:54



# psradm
- Change processor operational status

To bring the processor off-line:
# psradm -f

eg:
# psradm -f 1

Output:
bash-3.00# psradm -f 1
bash-3.00# psrinfo
0 on-line since 08/18/2009 12:43:45
1 off-line since 08/18/2009 16:19:39



To bring back the processor on-line:
# psradm -n

Eg:
# psradm -n 1

To gather the processor staus:
# psrinfo

Output:
bash-3.00# psrinfo
0 on-line since 08/18/2009 12:43:45
1 on-line since 08/18/2009 12:43:54


To bring the processor off-line:
# psradm -f

eg:
# psradm -f 1

Output:
bash-3.00# psradm -f 1
bash-3.00# psrinfo
0 on-line since 08/18/2009 12:43:45
1 off-line since 08/18/2009 16:19:39


To bring back the processor on-line:
# psradm -n

Eg:
# psradm -n 1

Output:
bash-3.00# psradm -n 1
bash-3.00# psrinfo
0 on-line since 08/18/2009 12:43:45
1 on-line since 08/18/2009 16:21:50


Note:
Where
# psradm -n = Bring the specified processor on-line
# psradm -f = Bring the specified processor off-line


Note:
The processor can be brought on-line and offline, whilst the machine is in on state.