Proware EP-4643S2D2-F8S6, User Manual

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Fibre to SAS/SATA Disk Array
116 User Manual
HDD Read Ahead Cache:
This option allows the users to disable the cache of the HDDs on the RAID Subsystem.
In some HDD models, disabling the cache in the HDD is necessary to prove the RAID
Subsystem functions correctly. When Enabled, the drive’s read ahead cache
algorithm is used, providing maximum performance under most circumstances.
Volume Data Read Ahead:
This option allows the users to set the Volume Data Read Ahead function. Options
are: Normal, Aggressive, Conservative, and Disabled.
HDD Queue Depth:
The queue depth is the number of I/O operations that can be run in parallel on a disk
drive. This parameter is adjusted the queue depth capacity of NCQ (SATA HDD) or
Tagged Command Queuing (SAS HDD) which transmits multiple commands to a single
target without waiting for the initial command to complete. HDD Queue Depth options
are 1, 2, 4, 8, 16, and 32.
Auto Activate Incomplete Raid
When some of the disk drives are removed in power off state or boot up stage, the RAID
set state will change to “Incomplete State”. But if a user wants to automatically continue
to work while the RAID controller is powered on, the user can set the “Auto Activate
Incomplete Raid” option to enable. The RAID state will change to “Degraded Mode” while
it powers on.
Disk Write Cache Mode:
The Disk Array supports Disk Write Cache Mode options: Auto, Enabled, and Disabled. If the
Disk Array has BBM (battery backup module), selecting the Auto option will automatically
enable Disk Write Cache. On the other hand, if there is no BBM, the Auto option will disable
Disk Write Cache.
Hot Plugged Disk For Rebuilding
It defines if the RAID array volume should start rebuilding or not when detects a disk is
inserted/re-inserted during online.
The options are: Blank Disk Only, Always, and Disable. The default is
Blank Disk Only .
Blank Disk Only: it will trigger the rebuilding if and only if the inserted disk has not
been in the RAID array before, which has no RAID signature on it. So when a
previously removed disk is self re-inserted, it won’t trigger the degraded RAID array
to rebuild, and so that the administrator has a chance to identify this misbehaving
disk and replaces it.
Always: it is what it was before. Whenever a disk is inserted/ re-inserted whether
new or previously existed, it always trigger a rebuilding for the Degraded RAID
set/Volume.
Disable: it will not trigger rebuilding regardless what sort of disk plugging in. When
Disable and/or Blank Disk Only is selected, the re-inserted/previously removed disk
will be identified as a disk in a separate RAID set with duplicated RAIDset# and with
all the rest of RAID members missing.