I recently had to cap the number of active CPUs on a bare metal ODA X5-2, and I noticed that the procedure is slightly different from what I used in the past (link to initial post).

Perform the following steps to generate the Core Key:

• Login to My Oracle Support (MOS) and click the submenu Systems.
• Select the serial number of the appliance and click on “Core Configuration”in the Asset Details Screen
• Select Manage Key
• From the Combo list select the number of cores to activate  and click Generate Key to generate the key.
• Click Copy Key to Clipboard to copy the key to the clipboard.
• Paste the key into an empty text file and save the file to a location on the Oracle Database Appliance.

ODA X5-2 initial number of CPU Cores

[root@odax5-2n0 ~]# cat /proc/cpuinfo | grep -i processor
processor : 0
processor : 1
processor : 2
processor : 3
...
...
..
.
processor : 70
processor : 71

[root@odax5-2n0 ~]# cat /proc/cpuinfo | grep -i processor |wc -l
72
[root@odax5-2n0 ~]#

Checks before enforcing the CPU restriction:

[root@odax5-2n0 ~]# oakcli show server

Power State : On
 Open Problems : 0
 Model : ODA X5-2
 Type : Rack Mount
 Part Number : xxxxxxxxxxx
 Serial Number : nnnnXXXXnnX <<<<<<<<<<<< This serial MUST match on BOTH of the ODA servers
 Primary OS : Not Available
 ILOM Address : 192.168.21.35
 ILOM MAC Address : xx:xx:xx:xx:xx:xx
 Description : Oracle Database Appliance X5-2 nnnnXXXXnnX
 Locator Light : Off
 Actual Power Consumption : 345 watts
 Ambient Temperature : 21.250 degree C
 Open Problems Report : System is healthy

[root@odax5-2n0 ~]#


[root@odax5-2n1 /]# oakcli show server

Power State : On
 Open Problems : 0
 Model : ODA X5-2
 Type : Rack Mount
 Part Number : xxxxxxxxxxx
 Serial Number : nnnnXXXXnnX <<<<<<<<<<<< This serial MUST match on BOTH of the ODA servers 
 Primary OS : Not Available
 ILOM Address : 192.168.21.36
 ILOM MAC Address : xx:xx:xx:xx:xx:xx
 Description : Oracle Database Appliance X5-2 nnnnXXXXnnX
 Locator Light : Off
 Actual Power Consumption : 342 watts
 Ambient Temperature : 21.750 degree C
 Open Problems Report : System is healthy

[root@odax5-2n1 /]#

[root@odax5-2n0 ~]# oakcli show env_hw
BM ODA X5-2
Public interface : COPPER
[root@odax5-2n0 ~]#


[root@odax5-2n1 /]# oakcli show env_hw
BM ODA X5-2
Public interface : COPPER
[root@odax5-2n1 /]#


[root@odax5-2n0 ~]# ipmitool -I open sunoem getval /X/system_identifier
Target Value: Oracle Database Appliance X5-2 nnnnXXXXnnX
[root@odax5-2n0 ~]# fwupdate list sp_bios
==================================================
SP + BIOS
==================================================
ID Product Name ILOM Version BIOS/OBP Version XML Support
---------------------------------------------------------------------------------------------------------------
sp_bios ORACLE SERVER X5-2 v3.2.4.52 r101649 30050100 N/A
[root@odax5-2n0 ~]#

[root@odax5-2n1 /]# ipmitool -I open sunoem getval /X/system_identifier
Target Value: Oracle Database Appliance X5-2 nnnnXXXXnnX
[root@odax5-2n1 /]# fwupdate list sp_bios
==================================================
SP + BIOS
==================================================
ID Product Name ILOM Version BIOS/OBP Version XML Support
---------------------------------------------------------------------------------------------------------------
sp_bios ORACLE SERVER X5-2 v3.2.4.52 r101649 30050100 N/A
[root@odax5-2n1 /]#

Apply the CPU Key form the first ODA node

[root@odax5-2n0 ~]# /opt/oracle/oak/bin/oakcli apply core_config_key /root/ODA_PROD_CPU_KEY_SerialNumber_NumberofCores_Configkey.txt
INFO: Both nodes will be rebooted automatically after applying the license
Do you want to continue: [Y/N]?:
Y
INFO: User has confirmed for reboot


Please enter the root password:

............Completed

INFO: Applying core_config_key on '192.168.16.25'
... 
INFO : Running as root: /usr/bin/ssh -l root 192.168.16.25 /tmp/tmp_lic_exec.pl
INFO : Running as root: /usr/bin/ssh -l root 192.168.16.25 /opt/oracle/oak/bin/oakcli enforce core_config_key /tmp/.lic_file
Waiting for the Node '192.168.16.25' to reboot..................................
Node '192.168.16.25' is rebooted
Waiting for the Node '192.168.16.25' to be up before applying the license on the node '192.168.16.24'.
INFO: Applying core_config_key on '192.168.16.24'
...
INFO : Running as root: /usr/bin/ssh -l root 192.168.16.24 /tmp/tmp_lic_exec.pl
INFO : Running as root: /usr/bin/ssh -l root 192.168.16.24 /opt/oracle/oak/bin/oakcli enforce core_config_key /tmp/.lic_file

Broadcast message from root@odax5-2n0
 (unknown) at 11:03 ...

The system is going down for reboot NOW!
[root@odax5-2n0 ~]#

New CPU cores configuration

[root@odax5-2n0 ~]# /opt/oracle/oak/bin/oakcli show core_config_key

Host's serialnumber = nnnnXXXXnnX
Enabled Cores (per server) = 6
Total Enabled Cores (on two servers) = 12
Server type = X5-2 -> Oracle Server X5-2
Hyperthreading is enabled. Each core has 2 threads. Operating system displays 12 processors per server
[root@odax5-2n0 ~]#

[root@odax5-2n1 ~]# /opt/oracle/oak/bin/oakcli show core_config_key

Host's serialnumber = nnnnXXXXnnX
Enabled Cores (per server) = 6
Total Enabled Cores (on two servers) = 12
Server type = X5-2 -> Oracle Server X5-2
Hyperthreading is enabled. Each core has 2 threads. Operating system displays 12 processors per server
[root@odax5-2n1 ~]#