Open System Services Management and Operations Guide (G06.30+, H06.08+, J06.03+)

This command will stop all filesets in the correct order. This command begins with the last
fileset mounted and stops the filesets in the reverse order in which they were last started.
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”
(page 146)
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.
Disabling OSS file caching changes the fault tolerant behavior of the fileset. Turning it off converts
OSSBUFFERED behavior to DP2BUFFERED behavior or OSSBUFFEREDCP behavior to
DP2BUFFEREDCP behavior.
The caching status of a file can change as opens, closes, and other events occur on the file. The
data integrity of a file and the access (data transfer) speed for the file are affected by the following:
• Whether OSS file caching is enabled
• Where data is buffered and when it is checkpointed, as controlled by the settings for the fileset
FTIOMODE fault-tolerance attribute and the NORMALIOMODE attribute
• Which program access options are used, such as how the file is opened
When OSS file caching is enabled, behavior comparable to that experienced on a node running
an RVU prior to G06.27 occurs when the NORMALIOMODE fileset attribute is OSSBUFFERED
and the FTIOMODE fileset attribute is UNBUFFEREDCP.
156 Managing Filesets