Product specifications

Host-Side and Drive-Side Parameters
8-13
Figure 5 - 14: Selecting Maximum Tag Count
This sub-menu facilitates the support for both Tagged Command
Queuing (TCQ) and Native Command Queuing (NCQ). TCQ is a
traditional feature on SCSI or Fibre disk drives, while NCQ is
recently implemented with SATA disk drives. The queuing feature
requires the support of both host adapters and hard disk drives.
Command queuing can intelligently reorder host requests to
streamline random accesses for IOPS/multi-user environments.
Infortrend’s subsystems support tag command queuing with an
adjustable maximum tag count from 1 to 128. The default setting is
“Enabled” with a maximum tag count of 32 (SCSI or Fibre drives) or
16 (default for SATA drives). Choose “Maximum Tag Count”, then
press [ENTER]. A list of available tag count numbers displays.
Move the cursor bar to a number, then press [ENTER]. Choose Yes
in the dialog box that follows to confirm the setting.
IMPORTANT!
• Every time you change this setting, you must reset the
controller for the changes to take effect.
• Disabling Tag Command Queuing will disable the hard drives’
built-in cache for Write-Back operation.
NOTE:
The following options are categorized as related to array
maintenance and data integrity:
• Periodic Drive Check Time
• Periodic Auto-Detect Failure Drive Swap Check Time
• Auto-Assign Global Spare Drive
Details of these options can be found in Chapter 10.
Another option is associated with disk drive SMART support and
details can be found in Chapter 12:
• Drive Predictable Failure Mode (SMART)