Creating a IBM Spectrum Scale cluster

Create a IBM® Spectrum Scale cluster with three quorum nodes from the sample IBM Spectrum Scale cluster template.

Before you begin

The IBM Spectrum Cluster Foundation Community Edition management node is installed.
The IBM Spectrum Scale base and update packages, along with the corresponding YUM repositories, are found on the IBM Spectrum Cluster Foundation Community Edition management node. Refer to Preparing for a IBM Spectrum Scale cluster deployment.
Servers that are added to the GPFS cluster must have at least two disks. One disk is used for the OS, and one disk is used for GPFS. For example: /dev/sda is used for the OS and /dev/sdb for GPFS.
Tip: To ensure that servers with two disks are added to the GPFS cluster, tag these servers as GPFS servers before you create a GPFS cluster. Then, when you create a GPFS cluster, use only the servers that are tagged as GPFS servers. See more on Tagging nodes.

Procedure

Log in to IBM Spectrum Cluster Foundation Community Edition management node as a root user.
Publish the sample IBM Spectrum Scale cluster template.
1. From the Resources tab, go to Cluster Templates and modify the sample IBM Spectrum Scale cluster template. Select the sample cluster template from the cluster template list and click Modify.
2. In the Cluster Template Designer, modify the GPFSNode tier. In the main canvas area (in the top portion of the window), click the GPFSServer server template (that is, the green GPFSServer rectangle in layer 2).
  - In the details pane (in the bottom portion of the window), click the OS Image tab, and set the image profile to the default stateful image profile.
  - Click the Network Profile tab, and set the network profile to the default network profile.
  - Click the Servers tab, and use the node tag feature to specify which nodes to use for the IBM Spectrum Scale cluster. If you previously created a tag to identify the specific servers to use, select the Select servers with all of the specified tags option and add the existing tag. If you do not have an existing tag, create one and make sure to use the new tag to tag the IBM Spectrum Scale servers before you add them to the IBM Spectrum Scale cluster.
3. Save your changes by clicking the save icon at the upper right.
4. Close the Cluster Template Designer to return to the Cluster Templates page.
5. From the list of cluster templates, select the sample IBM Spectrum Scale cluster template that was modified, and click Manage > Publish.

Using the published sample IBM Spectrum Scale cluster template, create a IBM Spectrum Scale cluster.

From the Clusters tab, go to Clusters and click Create.
Select the sample IBM Spectrum Scale cluster template and click Next.
Under the Servers tab, change the Minimum Number of Servers to 3.

Under the User-defined Variables tab, set the following variable values:

Variable	Value
`GPFS_Base_URL`	http://`@MANAGEMENT_NODE@`/install/gpfs/base Note: Replace `@MANAGEMENT_NODE@` with the IBM Spectrum Cluster Foundation Community Edition management node IP address.
`GPFS_Update_URL`	http://`@MANAGEMENT_NODE@`/install/gpfs/update Note: Replace `@MANAGEMENT_NODE@` with the IBM Spectrum Cluster Foundation Community Edition management node IP address.
`GPFS_Enable_FPO`	No
`GPFS_Num_Quorum`	3
`GPFS_Block_Size`	256 K
`GPFS_Rep_Factor`	2

Leave the other variables set to their defaults, and click Create.

In the Clusters page, view the cluster status. When the status is set to Active, the cluster is fully deployed.

Results

A new IBM Spectrum Scale cluster with 3 quorum nodes is deployed and active. A new IBM Spectrum Scale file system is created and each quorum node’s disk is added to the IBM Spectrum Scale file system.

What to do next

Verify that the IBM Spectrum Scale cluster is running correctly and that the IBM Spectrum Scale nodes are working correctly. To verify that the nodes are working correctly, log in to the first IBM Spectrum Scale quorum node (defined by the GPFS_Primary_Quorum_Node variable) via SSH and complete the following verification tasks:

To verify that the total number of quorum nodes is set to 3, the quorum value is set to 2 and that quorum is achieved, run the following:
```
# mmgetstate -s
```
To verify that all 3 servers are quorum nodes in active state, run the following command:
```
# mmgetstate -a -L
```
To verify that the servers are licensed as GPFS server nodes, run the following:
```
# mmlslicense -L
```
To verify that the FPO features are disabled for the system pool, check that theallowWriteAffinity attribute for the system pool is set to no by running the following command:
```
# mmlspool gpfsmntdata system -L
```
To verify that the GPFS file system has a block size of 256K, run the following:
```
# mmlsfs gpfsmntdata -B
```
To verify that the GPFS file system has a replication factor of 2, run the following:
```
# mmlsfs gpfsmntdata -r -m
```
Verify that all 3 disks are added to the gpfsmntdata file system, by ensuring that each disk comes from each GPFS node. Run the following:
```
# mmlsfs gpfsmntdata -d
```
To verify that all 3 nodes are mounting the GPFS file system, run the following:
```
# mmlsmount gpfsmntdata -L
```
Check the post-install-gpfs.log and post-config-gpfs.log log files in the /var/log/pcm directory. There should be no errors.