Compaq HSZ80 manual Through caching to its units Less than

1–27

	Table 1–9	Resulting Cache Policies and ECB Status (Continued)
Cache Module Status		Cache Policy
Cache A	Cache B	Unmirrored Cache	Mirrored Cache
Failed	At least	Data loss: No.	Data loss: No.
	50%	Cache policy: Controller A supports	Cache policy: Both controllers continue
	charged
		write-through caching only;	to support write-back caching.
		controller B supports write-back	Failover: No.
		caching.
		Failover: In transparent failover, all
		units failover to controller B and
		operate normally.
		In multiple-bus failover with host-
		assist, only those units that use
		write-back caching, such as
		RAIDsets and mirrorsets, failover to
		controller B.
		In single-controller configurations,
		the controller only provides write-
		through caching to its units.
Less than	Less than	Data loss: No.	Data loss: No.
50%	50%	Cache policy: Both controllers	Cache policy: Both controllers support
charged	charged
		support write-through caching only.	write-through caching only.
		Failover: No.	Failover: No.

Compaq HSZ80 Array Controller ACS Version 8.3 Configuration and CLI Reference Guide