342 DS8800 Performance Monitoring and Tuning
9.2.3 General Parallel File System (GPFS)
GPFS is a concurrent filesystem that can be shared among the nodes that compose a cluster
through a SAN or through a high-speed TCP/IP network. Beginning with Version 2.3, GPFS
does not require an LVM or a PowerHA cluster. You use it for sharing data among the servers
of a cluster concurrently without losing the facility to manipulate files that a standard
filesystem provides. It implements Direct I/O and filesystem caching among other features.
GPFS memory buffers
The pagepool sets the size of buffer cache on each node. For a database system, 100 MB
might be enough. For an application with many small files, you might need to increase this
setting to 2 GB - ...