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Cluster Server 8.0.2 Configuration and Upgrade Guide - AIX

Last Published: 2023-06-05

Product(s): InfoScale & Storage Foundation (8.0.2)

Platform: AIX

Setting up server-based I/O fencing using installer

You can configure server-based I/O fencing for the VCS cluster using the installer.

With server-based fencing, you can have the coordination points in your configuration as follows:

Combination of CP servers and SCSI-3 compliant coordinator disks
CP servers only
Veritas also supports server-based fencing with a single highly available CP server that acts as a single coordination point.

See About planning to configure I/O fencing.

This section covers the following example procedures:

Mix of CP servers and coordinator disks	See “To configure server-based fencing for the VCS cluster (one CP server and two coordinator disks)”.
Single CP server	See “To configure server-based fencing for the VCS cluster”.

To configure server-based fencing for the VCS cluster (one CP server and two coordinator disks)

Depending on the server-based configuration model in your setup, make sure of the following:
- CP servers are configured and are reachable from the VCS cluster. The VCS cluster is also referred to as the application cluster or the client cluster.
  See Setting up the CP server.
- The coordination disks are verified for SCSI3-PR compliance.
  See Checking shared disks for I/O fencing.
Start the installer with the -fencing option.
```
# /opt/VRTS/install/installer  -fencing
```
The installer starts with a copyright message and verifies the cluster information.
Note the location of log files which you can access in the event of any problem with the configuration process.
Confirm that you want to proceed with the I/O fencing configuration at the prompt.
The program checks that the local node running the script can communicate with remote nodes and checks whether VCS 8.0.2 is configured properly.
Review the I/O fencing configuration options that the program presents. Type 1 to configure server-based I/O fencing.
```
Select the fencing mechanism to be configured in this
Application Cluster [1-3,b,q] 1
```
Make sure that the storage supports SCSI3-PR, and answer y at the following prompt.
```
Does your storage environment support SCSI3 PR? [y,n,q] (y)
```
Provide the following details about the coordination points at the installer prompt:
- Enter the total number of coordination points including both servers and disks. This number should be at least 3.
```
Enter the total number of co-ordination points including both 
Coordination Point servers and disks: [b] (3)
```
- Enter the total number of coordinator disks among the coordination points.
```
Enter the total number of disks among these: 
[b] (0) 2
```
Provide the following CP server details at the installer prompt:
- Enter the total number of virtual IP addresses or the total number of fully qualified host names for each of the CP servers.
```
How many IP addresses would you like to use to communicate
 to Coordination Point Server #1?: [b,q,?] (1) 1
```
- Enter the virtual IP addresses or the fully qualified host name for each of the CP servers. The installer assumes these values to be identical as viewed from all the application cluster nodes.
```
Enter the Virtual IP address or fully qualified host name #1 
for the HTTPS Coordination Point Server #1: 
[b] 10.209.80.197
```
  The installer prompts for this information for the number of virtual IP addresses you want to configure for each CP server.
- Enter the port that the CP server would be listening on.
```
Enter the port that the coordination point server  10.209.80.197
would be listening on or accept the default port
suggested: [b] (443)
```
Provide the following coordinator disks-related details at the installer prompt:
- Choose the coordinator disks from the list of available disks that the installer displays. Ensure that the disk you choose is available from all the VCS (application cluster) nodes.
  The number of times that the installer asks you to choose the disks depends on the information that you provided in step 6. For example, if you had chosen to configure two coordinator disks, the installer asks you to choose the first disk and then the second disk:
```
Select disk number 1 for co-ordination point

1) rhdisk75
2) rhdisk76
3) rhdisk77

Please enter a valid disk which is available from all the 
cluster nodes for co-ordination point [1-3,q] 1
```
- If you have not already checked the disks for SCSI-3 PR compliance in step 1, check the disks now.
  The installer displays a message that recommends you to verify the disks in another window and then return to this configuration procedure.
  Press Enter to continue, and confirm your disk selection at the installer prompt.
- Enter a disk group name for the coordinator disks or accept the default.
```
Enter the disk group name for coordinating disk(s): 
[b] (vxfencoorddg) 
```

Verify and confirm the coordination points information for the fencing configuration.

For example:

Total number of coordination points being used: 3
Coordination Point Server ([VIP or FQHN]:Port): 
    1. 10.209.80.197 ([10.209.80.197]:443)
SCSI-3 disks:
    1. rhdisk75
    2. rhdisk76
Disk Group name for the disks in customized fencing: vxfencoorddg
Disk policy used for customized fencing: dmp

The installer initializes the disks and the disk group and deports the disk group on the VCS (application cluster) node.

Verify and confirm the I/O fencing configuration information.

CPS Admin utility location: /opt/VRTScps/bin/cpsadm     
Cluster ID: 2122
Cluster Name: clus1
UUID for the above cluster: {ae5e589a-1dd1-11b2-dd44-00144f79240c}

Review the output as the installer updates the application cluster information on each of the CP servers to ensure connectivity between them. The installer then populates the /etc/vxfenmode file with the appropriate details in each of the application cluster nodes.

Updating client cluster information on Coordination Point Server 10.209.80.197

Adding the client cluster to the Coordination Point Server 10.209.80.197 .......... Done

Registering client node sys1 with Coordination Point Server 10.209.80.197...... Done
Adding CPClient user for communicating to Coordination Point Server 10.209.80.197 .... Done
Adding cluster clus1 to the CPClient user on Coordination Point Server 10.209.80.197 .. Done

Registering client node sys2 with Coordination Point Server 10.209.80.197 ..... Done
Adding CPClient user for communicating to Coordination Point Server 10.209.80.197 .... Done
Adding cluster clus1 to the CPClient user on Coordination Point Server 10.209.80.197 ..Done

Updating /etc/vxfenmode file on sys1 .................................. Done
Updating /etc/vxfenmode file on sys2 ......... ........................ Done

See About I/O fencing configuration files.

Review the output as the installer stops and restarts the VCS and the fencing processes on each application cluster node, and completes the I/O fencing configuration.

Configure the CP agent on the VCS (application cluster). The Coordination Point Agent monitors the registrations on the coordination points.

Do you want to configure Coordination Point Agent on 
the client cluster? [y,n,q] (y) 

Enter a non-existing name for the service group for 
Coordination Point Agent: [b] (vxfen)

Additionally the coordination point agent can also monitor changes to the Coordinator Disk Group constitution such as a disk being accidently deleted from the Coordinator Disk Group. The frequency of this detailed monitoring can be tuned with the LevelTwoMonitorFreq attribute. For example, if you set this attribute to 5, the agent will monitor the Coordinator Disk Group constitution every five monitor cycles.
Note that for the LevelTwoMonitorFreq attribute to be applicable there must be disks as part of the Coordinator Disk Group.
```
Enter the value of the LevelTwoMonitorFreq attribute: (5)   
```

Enable auto refresh of coordination points.

Do you want to enable auto refresh of coordination points
if registration keys are missing 
on any of them? [y,n,q,b,?]  (n)

Note the location of the configuration log files, summary files, and response files that the installer displays for later use.
Verify the fencing configuration using:
```
# vxfenadm -d
```
Verify the list of coordination points.
```
# vxfenconfig -l
```

To configure server-based fencing for the VCS cluster

Make sure that the CP server is configured and is reachable from the VCS cluster. The VCS cluster is also referred to as the application cluster or the client cluster.
See Setting up the CP server.
Start the installer with -fencing option.
```
# /opt/VRTS/install/installer   -fencing
```
The installer starts with a copyright message and verifies the cluster information.
Note the location of log files which you can access in the event of any problem with the configuration process.
Confirm that you want to proceed with the I/O fencing configuration at the prompt.
The program checks that the local node running the script can communicate with remote nodes and checks whether VCS 8.0.2 is configured properly.
Review the I/O fencing configuration options that the program presents. Type 1 to configure server-based I/O fencing.
```
Select the fencing mechanism to be configured in this
Application Cluster [1-7,q] 1
```
Make sure that the storage supports SCSI3-PR, and answer y at the following prompt.
```
Does your storage environment support SCSI3 PR? [y,n,q] (y)
```
Enter the total number of coordination points as 1.
```
Enter the total number of co-ordination points including both 
Coordination Point servers and disks: [b] (3) 1
```
Read the installer warning carefully before you proceed with the configuration.
Provide the following CP server details at the installer prompt:
- Enter the total number of virtual IP addresses or the total number of fully qualified host names for each of the CP servers.
```
How many IP addresses would you like to use to communicate
to Coordination Point Server #1? [b,q,?] (1) 1
```
- Enter the virtual IP address or the fully qualified host name for the CP server. The installer assumes these values to be identical as viewed from all the application cluster nodes.
```
Enter the Virtual IP address or fully qualified host name
#1 for the Coordination Point Server #1: 
[b] 10.209.80.197
```
  The installer prompts for this information for the number of virtual IP addresses you want to configure for each CP server.
- Enter the port that the CP server would be listening on.
```
Enter the port in the range [49152, 65535] which the 
Coordination Point Server 10.209.80.197 
would be listening on or simply accept the default 
port suggested: [b] (443)
```

Verify and confirm the coordination points information for the fencing configuration.

For example:

Total number of coordination points being used: 1
Coordination Point Server ([VIP or FQHN]:Port): 
    1. 10.209.80.197 ([10.209.80.197]:443)

Verify and confirm the I/O fencing configuration information.

CPS Admin utility location: /opt/VRTScps/bin/cpsadm     
Cluster ID: 2122
Cluster Name: clus1
UUID for the above cluster: {ae5e589a-1dd1-11b2-dd44-00144f79240c}

The installer also populates the /etc/vxfenmode file with the entry single_cp=1 for such single CP server fencing configuration.

Updating client cluster information on Coordination Point Server 10.209.80.197

Adding the client cluster to the Coordination Point Server 10.209.80.197 .......... Done

Registering client node sys1 with Coordination Point Server 10.209.80.197...... Done
Adding CPClient user for communicating to Coordination Point Server 10.209.80.197 .... Done
Adding cluster clus1 to the CPClient user on Coordination Point Server 10.209.80.197 .. Done

Registering client node sys2 with Coordination Point Server 10.209.80.197 ..... Done
Adding CPClient user for communicating to Coordination Point Server 10.209.80.197 .... Done
Adding cluster clus1 to the CPClient user on Coordination Point Server 10.209.80.197 .. Done

Updating /etc/vxfenmode file on sys1 .................................. Done
Updating /etc/vxfenmode file on sys2 ......... ........................ Done

See About I/O fencing configuration files.

Review the output as the installer stops and restarts the VCS and the fencing processes on each application cluster node, and completes the I/O fencing configuration.

Configure the CP agent on the VCS (application cluster).

Do you want to configure Coordination Point Agent on the 
client cluster? [y,n,q] (y) 

Enter a non-existing name for the service group for 
Coordination Point Agent: [b] (vxfen)

Enable auto refresh of coordination points.

Do you want to enable auto refresh of coordination points
if registration keys are missing
on any of them? [y,n,q,b,?]  (n)

Note the location of the configuration log files, summary files, and response files that the installer displays for later use.