Clusters
Learn about using the Virtual I/O Server (VIOS) and creating a clustering configuration.
On VIOS Version 2.2.0.11, Fix Pack 24, Service Pack 1, you can create a cluster that consists of only one VIOS partition that is connected to the same shared storage pool. On VIOS Version 2.2.1.3, or later, you can create a cluster that consists of up to four networked VIOS partitions. On VIOS Version 2.2.2.0, or later, a cluster consists of up to 16 networked VIOS partitions. Thus, a cluster consists of up to 16 VIOS logical partitions with a shared storage pool that provides distributed storage access to the VIOS logical partitions in the cluster. Each cluster requires a separate repository disk and shared storage pool disks. The shared storage pool can be accessed by all VIOS logical partitions in the cluster.
All the VIOS logical partitions within a cluster must have access to all the physical volumes in a shared storage pool.
You can create and manage clusters by using the commands in the following table.
| Command | Description |
|---|---|
| cluster | Provides cluster management and listing capabilities. |
| chrepos | Replaces the repository disk. |
The following table lists the scalability limits for clusters in the VIOS Version 2.2.2.0, or later:
| Component | Minimum value | Maximum value |
|---|---|---|
| Number of VIOS systems in a cluster | 1 | 16 |
| Number of physical disks in the shared storage pool | 1 | 1024 |
| Number of logical unit mappings in the shared storage pool | 1 | 8192 |
| Number of client logical partitions per VIOS | 1 | 250 |
| Storage capacity of physical disks in the shared storage pool | 5 GB | 16 TB |
| Storage capacity of the shared storage | 5 GB | 512 TB |
| Storage capacity of a logical unit in the shared storage | 1 GB | 4 TB |
| Number of repository disks | 1 | 1 |
| Mirror copies | 1 | 2 |
| Number of mirror copies per shared storage pool | 1 | 2 |
