Downgrading Oracle Exadata InfiniBand Switches

Downgrade successfully updated Oracle Exadata InfiniBand switches to the older InfiniBand switch firmware version as determined by the current Oracle Exadata release.

Before you downgrade Oracle Exadata InfiniBand switches, complete the following checks on the Dom0 node used as the patch manager driving system:

Ensure that passwordless SSH as root works in both directions between each InfiniBand switch and the Dom0 node.
Verify that the SSH server on the Dom0 node does not close the Oracle Fleet Patching and Provisioning (Oracle FPP) connection used by the patch manager during a switch reboot. The effective ClientAliveInterval value must be 0 (disabled) or at least 2400 seconds (40 minutes). Run the following command on the Dom0 node to check the value:
```
sshd -T | grep '^clientaliveinterval '
```
Ensure that the Dom0 node has access to the physical InfiniBand fabric and can successfully run the following commands:
```
ibstat
ibnetdiscover -p
ibswitches
```

Check the current version of the Oracle Exadata InfiniBand switch patch.
Evaluate the current configuration and perform pre-downgrade checks for InfiniBand switches.
```
rhpctl update exadata -ibswitches comma_separated_list_of_IB_nodes -image image_name 
-client client_cluster_name -patchmgrargs "patch_manager_arguments" 
-patchmgrdrivingsystem patchmgr_driving_node -downgrade -eval
```
To evaluate the downgrade from the Oracle FPP Server using a Dom0 node as the patch manager driving system, run the following command:
```
rhpctl update exadata \
  -ibswitches comma_separated_list_of_IB_nodes \
  -image image_name -server \
  -fromnode dom0_node \
  -patchmgrdrivingsystem dom0_node \
  -path image_file_path -downgrade -eval
```
Specify the same Dom0 node for -fromnode and -patchmgrdrivingsystem. Specify the absolute path on the Dom0 node to which the image is copied for -path. Review and resolve any errors reported by the evaluation before you downgrade the switches.

Downgrade the Oracle Exadata InfiniBand switch patch.

rhpctl update exadata -ibswitches comma_separated_list_of_IB_nodes -image image_name 
-client client_cluster_name -patchmgrargs "patch_manager_arguments" 
-patchmgrdrivingsystem patchmgr_driving_node -downgrade

To downgrade the switches from the Oracle FPP Server using the Dom0 node, run the following command:

rhpctl update exadata \
  -ibswitches comma_separated_list_of_IB_nodes \
  -image image_name -server \
  -fromnode dom0_node \
  -patchmgrdrivingsystem dom0_node \
  -path image_file_path -downgrade

Check the current version of the Oracle Exadata InfiniBand switch patch to make sure that the downgrade is successful.