DATOptic RM12-S6.TB - Rackmount - Manual (Page 33)

WEB BROWSER-BASED CONFIGURATION
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an individual disk. JBOD does not provide data redundancy. User
needs to delete the RAID set, when you want to change the
option from the RAID to the JBOD function.
• SATA NCQ Support
The controller supports both SATA and SATA disk drives. The
SATA NCQ allows multiple commands to be outstanding within
a drive at the same time. Drives that support NCQ have an
internal queue where outstanding commands can be dynami-
cally rescheduled or re-ordered, along with the necessary
tracking mechanisms for outstanding and completed portions of
the workload. The 6Gb/s SATA RAID controller allows the user to
select the SATA NCQ support: “Enabled” or “Disabled”.
• HDD Read Ahead Cache
Allow Read Ahead (Default: Enabled)—When Enabled, the
drive’s read ahead cache algorithm is used, providing maximum
performance under most circumstances.
• Volume Data Read Ahead
The volume read data ahead parameter specifies the controller
firmware algorithms which process the Read Ahead data blocks
from the disk. The read ahead parameter is normal by default.
To modify the value, you must set it from the command line
using the Read Ahead option. The normal option satisfies the
performance requirements for a typical volume. The disabled
value implies no read ahead. The most efficient value for the
controllers depends on your application. Aggressive read ahead
is optimal for sequential access but it degrades random access.
• Empty HDD Slot LED
The firmware has added the "Empty HDD Slot LED" option to
setup the fault LED light "ON "or "OFF" when there is no HDD
installed. When each slot has a power LED for the HDD installed
identify, user can set this option to "OFF ". Choose option "ON",
the 6Gb/s SATA RAID controller will light the fault LED; if no
HDD installed.
• Max Command Length
Max Command Length is used to set a "best" IO size for the
RAID controller.