IBM Hub/Switch Installation Manual page 410

Chapter 6 HPSS Configuration
Table 6-33 Device/Drive Configuration Variables (Continued)
Display Field Name
Locate Support
NO-DELAY Support
Write TM(0) to Sync
Multiple Mover Tasks
SCSI-2 LBA Positioning
410
Description
An indication of whether
the device supports a high
speed (absolute)
positioning operation.
Advice: This option is supported for 3480, 3490, 3490E, 3590, 3580, Timberline,
Redwood, 9840, 9940, DST-312, DST-314, and GY-8240 devices.
An indication of whether
the device supports
opening the device with no
delay flag set, while
allowing tape I/O
operation after the open.
Advice: On some tape devices, this will allow for a quicker polling operation when
no tape is presently loaded in the device. This field is meaningful for tape devices
only. This option is not supported for the BMUX attached 3480, 3490, 3490E and
3590 devices.
An indication of whether
the device supports issuing
a write tape mark request
with a zero count to flush
data written previously to
the tape media.
Advice: On some devices, this may provide a higher performance method to ensure
that data has been safely written to the media. This option is not used for the 3480,
3490, 3490E, 3590, Timberline, and Redwood devices, provided the HPSS
supported device driver is used in accessing the device. Note that for Ampex DST-
312 this field should be set to "ON".
An indication of whether
the MVR should allow
multiple MVR tasks to
simultaneously access the
device.
Advice: This value is meaningful for disk devices only.
If ON, the tape device
supports SCSI-2 Logical
Block Addresses.
Advice: If SCSI-2 LBAs and the SCSI LOCATE command (Locate Support) are
supported by the device, HPSS will calculate destination LBAs based on known
LBAs and relative addresses. LBA positioning provides for faster access of data
residing on tape. The benefit will be realized for read requests with many source
descriptors specifying locations spread sparsely down the tape. This is only
supported with the IBM SCSI tape device driver.
September 2002
Acceptable Values
ON,
OFF
ON,
OFF
ON,
OFF
ON,
OFF
ON,
OFF
HPSS Installation Guide
Release 4.5, Revision 2
Default
Value
ON
ON
OFF
ON for disk,
OFF for tape
OFF