HP StorageWorks Clustered File System 3.2.1 Windows Storage Server Edition Administration Guide (February 2006)

Chapter 2: Introduction 9
• Support for standard filesystem operations such as assigning or de-
assigning drive letters. These operations can be performed with the
HP CFS Management Console or from the command line.
• 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.
HP Clustered File System Databases
HP Clustered File System uses the following databases to store cluster
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\Hewlett-Packard\HP Clustered File System\conf on each server.
These files should not be changed.
• Device database. HP Clustered File System uses a device database to
store the physical UID and a global device identifier for each disk
imported into the cluster. The database is located on the membership
partitions that you selected when installing HP Clustered File System.
The membership partitions are also used for functions related to SAN
control.
• Volume database. This database stores information about dynamic
volumes and is located on the membership partitions.
Virtual Hosts and Failover Protection
HP Clustered File System uses virtual hosts to provide failover protection
for servers and network applications.