Table 2–6 (Cont.) PARAMS Configuration Utility HSD05 Array Controller
Parameters
Parameter
Name
Definition
POWERONRST
Enables/disables issuing a SCSI BUS RESET command when the
system is turned on. The factory default for this parameter is 1
(enabled).
TRYSYNC
Enables/disables synchronous negotiation when a SCSI device is
initialized. For very short cables, synchronous negotiation can be
disabled for better performance in ASYNC mode rather than SYNC
mode. The factory default for this parameter is 1 (enabled).
SPIN_DOWN
Enables/disables the ability of the HSD05 array controller to
spin down drives or eject media when the operating system
issues a spin down command, such as the OpenVMS command
DISMOUNT/UNLOAD. The factory default for this parameter is 1
(enabled).
TAGGED_CMD
Enables/disables simple tag queuing. The factory default for this
parameter is 1 (enabled).
TRUNCATE
This parameter truncates the number of blocks to be divisible
by 126. The factory default for this parameter is 1. This default
supports faster OpenVMS volume shadowing catch-up time. A value
of 0 selects no truncation for compatibility with other third-party
units.
DEVICE_TYPE
This parameter applies to disk drives only. When disabled (set
to 0), the device type reported by the HSD05 array controller to
the OpenVMS operating system is an RA82™ disk drive. When
enabled, the HSD05 array controller reports the RF72™ device
type. The device type reported to the host does not affect the
accessible disk space. The factory default for this parameter is 1
(enabled).
IMMEDIATE
When enabled, this parameter causes the IMMEDIATE bit in the
SCSI START and STOP commands to be set. Note that when
IMMEDIATE is set to 0, the OpenVMS prompt does not return
until the drive’s media is ejected or the drive has spun down. The
factory default for this parameter is 1 (enabled).
CMD_P3
Determines the type of transmission used on the DSSI bus for
single host configurations only: 0 for standard and 1 for fast mode.
This is a hidden parameter that is not displayed by the PARAMS
SHOW /ALL, SHOW /SCSI, or SHOW /SCS commands. To display
this parameter value, use the SHOW CMD_P3 command in the
PARAMS utility. The factory default for this parameter is 1 (fast
mode).
TMARKSEARCH
Enables fast tape mark searching. Because some tape drives
perform slowly while looking for tape marks during operations
on large space records, a skip tapemark is done instead. Because
the device does not report the number of records skipped between
tapemarks, the position (object) count is not correct when this
parameter is enabled. The factory default for this parameter is 0
(disabled).
SHORT_TMARK
Enables/disables writing short filemarks on Exabyte® devices.
When disabled, all filemarks are written as large filemarks. The
factory default for this parameter is 1 (enabled).
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2–14 Preparing to Use the HSD05 Array Controller
