Open System Services Management and Operations Guide (G06.29+, H06.07+)

Managing Filesets
Open System Services Management and Operations Guide—527191-005
5-20
Changing OSS File Caching for the Disks of a
Fileset
3. At an SCF prompt, enter the following set of commands once for each disk volume
in the fileset:
STOP DISK diskname
ALTER DISK diskname, OSSCACHING ON
START DISK diskname
diskname
is the name of a disk volume that contains OSS files.
4. Restart the affected portion of the OSS file system by entering the following SCF
command one or more times:
START FILESET $ZPMON.filesetname
filesetname
is the name of each fileset that you previously stopped, specified in the order in
which mount points occur.
If you want to add disks to a storage pool for a fileset that has OSS file caching
disabled:
1. Use the Subsystem Control Facility (SCF) storage subsystem to add the disks to
the system.
2. Modify the storage-pool file for the fileset.
3. Do one of the following:
a. Stop and start the fileset as described under Starting (Mounting) or Restarting
Filesets on page 5-7
b. Apply the change to the started fileset using the SCF CONTROL FILESET
Command with the SYNC option.
OSS File Caching Overview
By default, the OSS environment provides a file cache for regular files in each
processor that does input or output with a disk volume that contains OSS files. HP
strongly recommends that you leave OSS file caching enabled. This cache is
necessary for the fault tolerant behavior controlled by the fileset FTIOMODE or
NORMALIOMODE attributes.
Enabling or disabling this feature does not affect access from the Guardian
environment to Guardian files (including SQL files) on a volume that contains OSS
regular files.
If you disable OSS file caching on a disk volume that is in a fileset, you must disable
OSS file caching on all disk volumes that you want to use for that OSS fileset. You
cannot predict which disk volume in a fileset will be used for a given file; if you have
OSS file caching enabled on one disk volume in a given fileset but disabled for another
disk volume in that fileset, you cannot predict whether a particular file might be cached.