Detailed Specifications, Caching | Dot Hill Systems 200 guide

Detailed Specifications

RAID

RAID levels	0, 1, 0+1, 3, 5, 1+0, 3+0 and 5+0. Enhanced RAID Levels
	supported with logical volume implementation.

Maximum number of logical drives	8

RAID level dependency to each logical	Independent. Logical drive configured in different RAID levels
drive	can co-exist in an array

Maximum number of drives for each logical	31 (RAID 3 or 5); 45 (RAID 0 or NRAID); 44 (RAID 0+1)
drive

Logical drive identification	Unique, controller randomly generated logical drive ID; Logical
	drive name user-configurable

Maximum partitions of each logical drive	32

Maximum number of logical drives in a	8
logical volume

Maximum number of logical volumes	8

Maximum number of LUN per host ID	Up to 32, user configurable

Concurrent I/O	Supported

Tag command queuing	Supported

Dedicated spare drive	Supported

Global spare drive	Supported

Co-existing dedicated and global spare	Supported
drives

Auto-rebuild onto spare drive	Supported

Auto-scan of replacement drive upon	Supported
manually initiated rebuild

Auto-rebuild onto failed drive replacement	Supported. With no spare drive assigned, the controller will auto-
	scan the failed drive and starts to rebuild automatically once the
	failed drive has been replaced.

Background firmware download	Firmware can be downloaded during active I/Os. Administrator
	may find appropriate time to reset controller later.

Auto recovery from logical drive failure	Supported.
	Caused when a user accidentally removes the wrong disk and
	causes a 2nd disk failure of a logical drive with one previously
	failed disk

Caching

Write-back cache	Supported

Write-through cache	Supported