Raid expansion, Redundant controllers, Raid e – Dot Hill Systems SANnet II 200 User Manual
Page 26: Xpansion, Edundant, Ontrollers

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
connection
Supported
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
replace drives
Supported
Replace members with drives of larger capacity.
Expand capacity with no extra drive bays
required
Supported in Mode 2 RAID expansion. Provide “Copy and
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
expansion
No operating environment driver required. No software has to be
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
controller mode
Supported
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
channel
RAID: SCSI; RCC Reset signals built-in
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