14
Hardware Installation and User’s Guide
Hardware Installation
2.5
Configurable Disk Drive SCSI Parameters
When a SCSI hard disk drive is initialized the first time by the RAID controller, its SCSI
parameters are automatically set to their optimal settings. Most settings are set
automatically and can not be configured manually. To view or configure disk drive SCSI
parameters from the Storage Console, choose Advanced Setup
Æ
Configure Physical
Devices
Æ
Select Physical Drive
Æ
SCSI Parameter/Initialize.
2.6
Configurable I/O Controller SCSI Parameters
When the controller starts up, its SCSI parameters are automatically set to their optimal
settings. Manual configuration is not required. However, you can customize I/O SCSI
parameters for each channel on the controller by using the Storage Console menu
Advanced Setup > Configure Controller > Controller Settings.
Table 2-1. Configurable Disk Drive SCSI Parameters
Parameter
Setting/
Value
Configuration
Description
Synch.
Transfer
Enabled /
Disabled
Automatic
This setting when enabled allows the controller to
operate in synchronous transfer mode
Synch.
Transfer Rate
Speed
(MB/sec)
Automatic
Allows for the setting of the speed for the SCSI
hard disks (up to 320 MB/sec for U320 drives).
No matter the setting, the SCSI bus will negotiate
the fastest speed up to this setting. Lowering the
setting will force the disk drive to transfer at the
lower speed.
Disconnect
Enabled /
Disabled
Automatic
Enabling this setting allows for the disk drive to
disconnect from the SCSI bus when it’s not
participating in a transfer. This allows for optimal
bus utilization by all devices on the bus.
Tagged
Queues
On / Off
Automatic
When enabled, this feature allows the SCSI disk
drive to execute more than one command at a
time.
Disk Read
and Write
Cache
On / Off
Configurable
For performance reasons, the
Read Ahead and
Write cache of the hard disk drives should always
be on. This is the default setting.
Table 2-2. Configurable I/O Controller SCSI Parameters
Parameter
Setting/Value
Description
Domain Validation
On / Off
When this is set to
On, Domain validation allows for a
cyclical check of the correct data transfer at a given rate for
the respective channel.
For ultra320, the GDT8500RZ controller supports Basic,
Enhanced, and Margined Domain Validation. For ultra160,
the GDT8500RZ controller supports Basic and Enhanced
Domain Validation.
