DATOptic RM12-S6.TB - Rackmount - Manual (Page 37)

WEB BROWSER-BASED CONFIGURATION
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• Timeout Setting
Disk time-out is a registry setting that defines the time that
RAID controller will wait for a hard disk to respond to a com-
mand. You can modify the retry value by entering a new value
in the edit box beside this button and then selecting the button.
Normally you should not need to modify this value. Default value
is 8 seconds: You can select between 3~8 second.
• Number of Retries
This setting determines the number of access that will be at-
tempted before the current command from the RAID controller
to the disk drive is aborted. You can modify the retry value by
entering a new value in the edit box beside this button and then
selecting the button. Normally you should not need to modify
this value. There are two selections, either 2 retry or 3 retry.
• Buffer Threshold
This new feature there are 3 options; 25%, 50%, 75%. The
percentage represents how much data should be kept in resi-
dent cache memory (how full cache should get) before controller
starts to flush data onto the hard drives. If the buffer is set for
25%, then all 25% will be cached and is used for writing data.
The remaining cache memory will be used for reading and other
system overhead. Write buffer threshold for 5% is added for
video recording. This option will push data to disk early.
This feature gives controller extra buffer time in case of slow re-
sponse from the hard drives within a given time. Consequently,
this can prevent a pause in data flow and there will be continued
data access and stream. This feature is very useful for the video
streaming applications where there is high demand for constant
non-stop data flow with no interruption due to lower perfor-
mance of specific hardware.
• Amount of Read Ahead
Read-Ahead data is buffered in the RAID controller cache,
however, thereby cutting down on the amount of I/O traffic to
the disk. The Amount of Read Ahead defines how many data of
reading at a time, making more efficient use of the RAID sub-
system. This makes it possible to locate and re-issue the data
without repetitive hard parsing activities.