8.10 Changing IP Addresses Used for Mirroring among Servers

This section describes the procedures to change IP addresses used for mirroring among servers.

Change both nodes to single user mode, and then perform the procedures.

Because the console cannot be used in a cloud environment (except an FJcloud-Baremetal environment), do not select single user mode. In this case, perform step 1 to 3 to restrict the automatic startup of the PRIMECLUSTER service.

In an environment other than a cloud environment (except an FJcloud-Baremetal environment), follow the procedure from step 4.

Stop RMS.
If RMS is running, execute the following command on any one node to stop RMS.
```
# hvshut -a
```
Note
If RMS is stopped on all nodes during the synchronization copying of the GDS volume, the synchronization copying of the entire volume area is performed after the corrections are applied and all nodes are restarted.
If you do not want to perform the synchronization copying of the entire area of volume, stop RMS after the synchronization copying is completed.
To check the slice status of the GDS volume, execute the following command.
Execute the following command on any one node to check the value of the STATUS field of the command output.
The status of the copy destination slice is COPY during the synchronization copying, and after copying is complete, the status becomes ACTIVE or STOP.
```
# sdxinfo -S
```
Restrict the automatic startup of the PRIMECLUSTER service.
Restrict the automatic startup of the PRIMECLUSTER service by executing the following command on all nodes.
```
# /opt/FJSVpclinst/bin/pclservice off
```
Restart the system.
Restart the system on all nodes.
```
# /sbin/shutdown -r now
```
Delete the registration of the target portal on the local node.
Example) when IP address for the mirroring among servers is 192.168.56.20
```
# iscsiadm -m discovery --op delete --portal 192.168.56.20
```
Start the network service.
For the cloud environment (except an FJcloud-Baremetal environment), this procedure is unnecessary because the network service has already been started.
- For RHEL7
```
# systemctl start network.service
```
The following message may be output but, no action is required because the operation is not affected.
```
Error getting authority: Error initializing authority: Could not connect:
No such file or directory (g-io-error-quark, 1)
```
- For RHEL8 or later
```
# systemctl start NetworkManager.service
```
Copy the setting information file of the iSCSI target.
Example) when the file name for the copy destination is /var/tmp/targetfile.json
```
# cp /etc/target/saveconfig.json /var/tmp/targetfile.json
```

Change the IP address described in the copy destination file in step 6.

Example) When changing the IP address for the mirroring among servers to 192.168.56.21

# vim /var/tmp/targetfile.json

[Before changing]

{
  "fabric_modules": [],
  "storage_objects": [
    {
...
          "portals": [
            {
              "ip_address": "192.168.56.20",
              "iser": false,
              "port": 3260
            }
          ],
...

[After changing]

{
  "fabric_modules": [],
  "storage_objects": [
    {
...
          "portals": [
            {
              "ip_address": "192.168.56.21",
              "iser": false,
              "port": 3260
            }
          ],
...

Reflect the setting information file of the iSCSI target edited in step 7 to the target.
Example) when the file name is /var/tmp/targetfile.json
```
# targetctl restore /var/tmp/targetfile.json
```
The following message may be output but, no action is required because the operation is not affected.
```
Unable to load target_core_user
```

Confirm that the iSCSI target was set correctly.

# targetcli /iscsi/ ls

Point

(*1) Confirm that the modified IP address was reflected.

[Output example]

o- iscsi .................................................................. [Targets: 1]
  o- iqn.2003-01.org.linux-iscsi.node1.x8664:sn.6e665c7c1be0 ................. [TPGs: 1]
    o- tpg1 ..................................................... [no-gen-acls, no-auth]
      o- acls ................................................................ [ACLs: 2]
      | o- iqn.1994-05.com.redhat:dee92ff9979d ........................ [Mapped LUNs: 1]
      | | o- mapped_lun0 ...................................... [lun0 block/store1 (rw)]
      | o- iqn.1994-05.com.redhat:fa7eb9cf483c ........................ [Mapped LUNs: 1]
      |   o- mapped_lun0 ...................................... [lun0 block/store1 (rw)]
      o- luns ................................................................ [LUNs: 1]
      | o- lun0 ................ [block/store1 (/dev/disk/by-id/scsi-3500000e111c56610)]
      o- portals .......................................................... [Portals: 2]
        o- 192.168.56.21:3260 ..................................................... [OK] (*1)

Store the target information that was restored in step 8.
```
# targetctl save
```
Change the IP addresses described in the /etc/opt/FJSVsdx/.sdxnetmirror_ipaddr file.
[Before changing]
```
192.168.56.10
192.168.56.20
```
[After changing]
```
192.168.56.11
192.168.56.21
```
Establish iSCSI session.
For the procedure, refer to "4.8.4 Establishing iSCSI Session."
Step 8 does not need to be performed.
Restart both nodes in multi-user mode.
In a cloud environment (except an FJcloud-Baremetal environment), take the following procedure to cancel restricting the automatic startup of the PRIMECLUSTER service.
1. Cancel restricting the automatic startup of the PRIMECLUSTER service.
  Execute the following command on all nodes and cancel the PRIMECLUSTER service settings restricted in step 2.
```
# /opt/FJSVpclinst/bin/pclservice on
```
2. Restart the system.
  Restart the system on all nodes.
```
# /sbin/shutdown -r now
```