SCF Reference Manual for the Storage Subsystem (G06.27+, H06.04+)

Storage Subsystem Commands
SCF Reference Manual for the Storage Subsystem—529937-008
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Disk Attribute Descriptions
CACHE { ( block-size, num-blocks ) |
( ( block-size, num-blocks ),
( block-size, num-blocks ) ) }
specifies the disk cache configuration for an in-use volume.
Disk cache configuration is the number and size of sectors read from disk and
stored in the processor for use as virtual memory. If you do not specify a value,
SCF uses values set by the disk process, which might cause performance
problems.
Before using this attribute, see Considerations for ALTER DISK, CACHE and
Magnetic Disks on page 6-23.
CACHESIZE number
is the number of entries of the name cache of the virtual disk process.
The name cache is used to hold entries in the audit-name table. number is in the
range 0 through 50000. The default is 0.
Avoid making the cache too small, which can adversely affect file-management
operations (such as FILE_OPEN_ and file information requests) serviced by a
virtual disk process.
CBPOOLLEN number
is the maximum memory (in 128-KB units) that can be allocated for open-related
data structures for the disk. The memory available for these structures limits the
total number of concurrent opens allowed on the disk. number is in the range 0
through 1000. The default is 1000.
You can increase the value of this attribute while the disk is in the STARTED state.
However, to decrease the value of this attribute, the disk must be in the STOPPED
state. As a result, this attribute value cannot be decreased for the system disk
Note. This attribute is not valid for the ADD DISK command and the PROFILE object.
block-size is a sector size in bytes or kilobytes:
512 or .5K
1024 or 1K
2048 or 2K
4096 or 4K
num-blocks is the number of blocks to be allocated in cache. The maximum
number of blocks is 2,097,152 regardless of block-size. The
minimum number of blocks is 18 multiplied by the number of disk
processes configured for the volume. Use the INFO DISK,
CONFIG command to display this value in the
NumDiskProcesses field.
Note. This attribute is only valid for virtual disks.