PFSFileSystem Section

The PFSFileSystem section describes the parallel file systems that Sun MPI applications can use. This description includes

• The name of the parallel file system.

• The hostname of each server node in the parallel file system.

• The name of the storage device to be included in the parallel file system being defined.

• The number of PFS I/O threads spawned to support each PFS storage device.

A separate PFSFileSystem section is needed for each parallel file system that you want to create. Example 2-5 shows a sample PFSFileSystem section with two parallel file systems, pfs-demo0 and pfs-demo1.

Example 2-5 PFSFileSystem Section Example

Begin PFSFileSystem=pfs-demo0
NODE            DEVICE              THREADS 
hpc-node0       /dev/rdsk/c0t1d0s2  1 
hpc-node1       /dev/rdsk/c0t1d0s2  1 
hpc-node2       /dev/rdsk/c0t1d0s2  1 
End PFSFileSystem

Begin PFSFileSystem=pfs-demo1
NODE            DEVICE              THREADS 
hpc-node3       /dev/rdsk/c0t1d0s2  1
hpc-node4       /dev/rdsk/c0t1d0s2  1 
End PFSFileSystem

Parallel File System Name

The first line shows the name of the parallel file system. PFS file system names must not include spaces.

Server Node Hostnames

The NODE column lists the hostnames of the nodes that function as servers for the parallel file system being defined. The example configuration in Example 2-5 shows two parallel file systems:

• pfs-demo0 - three server nodes: hpc-node0, hpc-node1, and hpc-node2.

• pfs-demo1 - two server nodes: hpc-node3 and hpc-node4.

Storage Device Names

The second column gives the device name associated with each member node. This name follows Solaris device naming conventions. (But note the use of rdisk in the device names.)

Thread Limits

The THREADS column allows the administrator to specify how many threads a PFS I/O daemon will spawn for the disk storage device or devices it controls. The number of threads needed by a given PFS I/O server node will depend primarily on the performance capabilities of its disk subsystem.

• For a storage object with a single disk or a small storage array, one thread may be enough to exploit the storage unit's maximum I/O potential.

• For a more powerful storage array, two or more threads may be needed to make full use of the available bandwidth.