3.4.0 Matrix Server Administration Guide

Chapter 1: Introduction 6

PSFS Filesystems

A PSFS filesystem can be created either on a dynamic volume created

with the Volume Manager or on a partition of a disk that has been

imported into the matrix.

The PSFS filesystem provides the following features:

• Concurrent access by multiple servers. After a filesystem has been

created on a shared disk, the filesystem is available to all matrix

servers having physical access to the device via the SAN.

• Support for standard filesystem operations such as assigning or de-

assigning drive letters. These operations can be performed with the

PolyServe Management Console or from the command line.

• Quotas for users, including both hard and soft limits.

• Support for existing applications. The PSFS filesystem uses standard

read/write semantics and does not require changes to applications.

• Journaling and live crash recovery. Filesystem metadata operations

are written to a journal before they are performed. If a server using the

filesystem should crash during an operation, the journal is replayed

and any journaled operations in progress at the time of the crash are

completed. Users on other servers will experience only a slight delay

in filesystem operations during the recovery.

Matrix Server Databases

Matrix Server uses the following databases to store matrix information:

• Shared Memory Data Store (SMDS). The SANPulse process stores

filesystem status information in this database. The database consists of

sp_status files that are located in %SystemDrive%\Program

Files\Polyserve\MatrixServer\conf on each server. These files should

not be changed.

• Device database. Matrix Server uses a device database to store the

physical UID and a global device identifier for each disk imported into

the matrix. The database is located on the membership partitions that

you selected when installing Matrix Server. The membership

partitions are also used for functions related to SAN control.