3.5.1 Matrix Server Administration Guide

Chapter 8: Configure MxFS-Linux 133

one of the networks already in use in the cluster. The administrator then

specifies both a primary node to host the Virtual NFS Service and an

ordered set of backup nodes to host the Virtual NFS Service in case of

failover. Finally, the administrator selects one Export Group to be

associated with the Virtual NFS Service. This Export Group defines which

exports will be available via NFS for this Virtual NFS Service.

It is possible to create multiple Virtual NFS Services and associate the

same Export Group with each one. This enables “scale-out” NFS service

for the same filesystems across multiple NFS servers in the cluster. It is

further possible to set up a DNS round robin configuration such that a

single IP address (or DNS name) can be used by all clients, yet the client

connections will be evenly distributed among the several Virtual NFS

Services running on separate nodes of the cluster. Other configurations

are possible.

Supported NFS Versions

MxFS-Linux supports versions 2 and 3 of the NFS file sharing protocols

based on UDP and TCP.

Tested Configuration Limits

MxFS-Linux has been tested to the following configuration limits:

• Up to 16 nodes in the matrix.

• 512 independent PSFS filesystems per matrix.

• 128 Virtual NFS Services per matrix.

• 64 Export Groups per matrix.

• 1024 export records per Export Group.

RPC Program Usage

RPC program 300277 (VNSM) supplements the standard Network Status

Monitor RPC program 100024 (NSM). VNSM allows the virtualization of

status monitoring on a per-Virtual NFS Service basis. One status

monitoring process on each cluster node is responsible for a varying

number of logically independent services (Virtual NFS Services). The

VNSM RPC program is used to manage the responsibilities of the status