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ASUS PCI-DA2200 User’s Manual
is still retrying or while a drive is unable to arbitrate the SCSI bus.
Setting the timeout to a greater value will cause the controller to
keep waiting for a drive, and it may sometimes cause a host timeout.
3.5.5
Maximum Tag Count
The maximum number of tags that can be sent to each drive at the
same time. A drive has a built-in cache that is used to sort all of the
I/O requests (“tags”) which are sent to the drive, allowing the drive
to finish the requests faster. The cache size and maximum number of
tags varies between different brands and models of drive. Using the
default setting – “32” – is highly recommended. Changing the
maximum tag count to “Disable” will cause the internal cache of the
drive to be ignored (i.e., not used).
3.5.6
Periodic Drive Check Time
The “Periodic Drive Check Time” is an interval for the controller to
check all of the drives that were on the SCSI bus at controller startup
(a list of all the drives that were detected can be seen under “View
and Edit SCSI Drives”). The default value is “Disabled”. “Disabled”
means that if a drive is removed from the bus, the controller will not
be able to know – so long as no host accesses that drive. Changing the
check time to any other value allows the controller to check – at the
selected interval – all of the drives that are listed under “View and
Edit SCSI Drives.” If any drive is then removed, the controller will be
able to know – even if no host accesses that drive.
3.5.7
SAF-TE Enclosure Monitoring
What is SAF-TE?
SAF-TE stands for SCSI Accessed Fault-Tolerant Enclosures. It is an
enclosure management technology that uses the SCSI bus to interact
with the controller. A SAF-TE-compliant enclosure monitors the fan
temperature, power supply, UPS and also provides drive status
LED’s.
How does it work?
The SAF-TE device, which is often a back-plane within a drive-bay
enclosure, must occupy a connector on one of the drive channels’
SCSI cables. The presence of a SAF-TE device will be detected and its
presence will be displayed in the BIOS configuration utility, Text
RAID Manager and the GUI RAID Manager programs. The RAID