Do not increase this parameter if you are in doubt. Each cached file requires space in the mallocpool for an i-node plus approximately 800 bytes of metadata. The only configuration parameter that directly addresses performance is priority . Sometimes called scheduling priority, this parameter sets the UNIX priority for the GPFS daemon. The default is 40.
Priority increases with lower values.
Virtual Shared Disks GPFS accesses data using the facilities of the Recoverable Virtual Shared Disk Licensed Program, and the Virtual Shared Disk component of the Parallel System Support Programs for AIX, which allows application programs executing on different SP nodes to access a logical volume as if it were local at each node. Recoverable Virtual Shared Disk, which allows a secondary or backup server to be defined for such a logical volume, is required even when there are no twin-tailed disks that can be physically accessed from more than one node because it provides fencing capabilities that preserve data integrity in the event of certain failures. Managing Shared Disks , SC23-3849, contains installation, management, and usage information for both Virtual Shared Disk and Recoverable Virtual Shared Disk. You can use SMIT or the mmchconfig command to change the following configuration attributes after the initial configuration has been set. Items 4 through 7 require that the nodes be rebooted before new values take effect.