Reverse Exadata Elastic Configuration using elastic config marker

As you may already know ,  The elastic configuration process will allow initial IP addresses to be assigned to database servers and cells, regardless of the exact customer configuration ordered. The customer specific configuration can then be applied to the nodes.

Sometime you can make mistakes and end up assigning wrong IP’s or hostnames to Exadata nodes. You can using Exadata elastic config marker to revert applied elastic configuration.

Problem : Applied wrong IP’s to Exadata Nodes 

[root@exdbadm01 linux-x64]# ibhosts
Ca : 0x0010e00001d4f7a8 ports 2 "exadbadm02 S 192.168.10.3,192.168.10.4 HCA-1"
Ca : 0x0010e00001d691f0 ports 2 "exaceladm03 C 192.168.10.9,192.168.10.10 HCA-1"
Ca : 0x0010e00001d68e30 ports 2 "exaceladm01 C 192.168.10.5,192.168.10.6 HCA-1"
Ca : 0x0010e00001d68cd0 ports 2 "exaceladm02 C 192.168.10.7,192.168.10.8 HCA-1"
Ca : 0x0010e00001d60e00 ports 2 "exadbadm01 S 192.168.10.1,192.168.10.2 HCA-1"

Solution : Create ./elasticConfig file at root on all Exadata nodes. Please note that all the IP’s will be changed to factory default.

create elastic marker on all nodes 

[root@node1 /]# cd /
[root@node1 /]# touch .elasticConfig
[root@node1 /]# reboot

Broadcast message from root@exdbadm01.itrans.int
(/dev/pts/0) at 18:38 ...

The system is going down for reboot NOW!

Login Again using factory default IP's 

[root@node8 linux-x64]# ibhosts
Ca : 0x0010e00001d4f7a8 ports 2 "node10 elasticNode 172.16.2.46,172.16.2.46 ETH0"
Ca : 0x0010e00001d691f0 ports 2 "node4 elasticNode 172.16.2.40,172.16.2.40 ETH0"
Ca : 0x0010e00001d68e30 ports 2 "node2 elasticNode 172.16.2.38,172.16.2.38 ETH0"
Ca : 0x0010e00001d68cd0 ports 2 "node1 elasticNode 172.16.2.37,172.16.2.37 ETH0"
Ca : 0x0010e00001d60e00 ports 2 "node8 elasticNode 172.16.2.44,172.16.2.44 ETH0"