User manual

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WEB BROWSER-BASED CONFIGURATION
• JBOD/RAID Conguration
JBOD is an acronym for “Just a Bunch Of Disk”. A group of hard
disks in a RAID controllers are not set up as any type of RAID
conguration. All drives are available to the operating system as
an individual disk. JBOD does not provide data redundancy. User
needs to delete the RAID set, when you want to change the op-
tion from the RAID to the JBOD function.
•
Maximun SATA Supported
The SATA RAID controller can support up to SATA ll, which runs
up to 300MB/s. NCQ is a command protocol in Serial ATA that
can only be implemented on native Serial ATA hard drives. It
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 dynamically rescheduled
or re-ordered, along with the necessary tracking mechanisms for
outstanding and completed portions of the workload. The RAID
subsystem allows user to choose the SATA mode (slowest to
fastest): SATA150, SATA150+NCQ, SATA300, SATA300+NCQ.
• HDD Read Ahead Cache
Allow Read Ahead (Default: Enabled)—When Enabled, the drive’s
read ahead cache algorithm is used, providing maximum perfor-
mance under most circumstances.
•
Stagger Power on
In a PC system with only one or two drives, the power is able to
supply enough power to spin up both drives simultaneously. But
in systems with more than two drives, the startup current from
spinning up the drives all at once can overload the power supply,
causing damage to the power supply, disk drives and other
system components. This damage can be avoided by allowing
the host to stagger the spin-up of the drives. New SATA drives
have support stagger spin-up capabilities to boost reliability.
Staggered spin-up is a very useful feature for managing multiple
disk drives in a storage subsystem. It gives the host the ability
to spin up the disk drives sequentially or in groups, allowing
the drives to come ready at the optimum time without straining
the system power supply. Staggering drive spin-up in a multiple
drive environment also avoids the extra cost of a power supply
designed to meet short-term startup power demand as well as
steady state conditions.