Dot Hill Systems 200 manual Detailed Specifications, Caching

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

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