Dot Hill Systems 200 manual RAID Expansion, Redundant Controllers

	Head: 64,127,255 or variable
	Cylinder: <1024, <32784,<65536 or variable
Drive motor spin-up	Supported
	The controller will send spin-up (start unit) command to each
	drive at 4 sec. intervals.
Drive-side tag command queue	Supported
	User adjustable up to 128 for each drive
Host-side maximum queued I/O count	Supported
	User adjustable up to 1024
Maximum concurrent host LUN connection	Supported
	User adjustable up to 64
Number of tags reserved for each host LUN	Supported
connection	User adjustable up to 256
Drive I/O timeout	Supported
	User adjustable
RAID Expansion
On-line RAID expansion	Supported
Mode-1 RAID expansion-add drive	Supported
	Multiple drives can be added concurrently.
Mode-2 RAID expansion – copy and	Supported
replace drives	Replace members with drives of larger capacity.
Expand capacity with no extra drive bays	Supported in Mode 2 RAID expansion. Provide “Copy and
required	Replace Drive” function to replace drives with drives of greater
	capacity. No need to add another enclosure for the extra drives.
Operating environment support for RAID	No operating environment driver required. No software has to be
expansion	installed for this purpose.
Redundant Controllers
Active-active redundant controller	Supported
Synchronized cache for both controllers	Supported
	Through a dedicated synchronizing channel, synchronized cache
	over Fibre loops is supported.
Write-back cache enabled in redundant	Supported
controller mode	Using synchronized cache connection between controllers.
Automatic failover	Supported
Automatic failback	Supported
Controller hot-swap	Supported
	Support on-line hot-swap of the failed controller. There is no need
	to reset or shutdown the failed controller. One redundant
	controller can be pulled out during use.
Redundant controller communication	RAID: SCSI; RCC Reset signals built-in
channel

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