SCF Reference Manual for the Storage Subsystem (G06.24+, H06.03+)

Storage Subsystem Commands
SCF Reference Manual for the Storage Subsystem—529937-007
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ALTER DISK Command
BACKUPSAC { number | name }
is the SAC that controls the backup path to the device.
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.
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.
number is the SAC subdevice number on the adapter.
If you specify BACKUPSAC in number format, you must also specify
BACKUPLOCATION.
name is the full name of the SAC location. For example:
SNDA.SAC-1.GRP-1.MOD-1.SLOT-53
FCSA.SAC-1.GRP-11.MOD-2.SLOT-5
Use this form to override the default selection of which adapter gets
the -P path and which gets the -B path.
An FCSA must be located in either MOD- 2 or MOD-3 of an IOAM
enclosure. There are five slots in each IOAM module
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.