Compaq HSZ80 manual 26General Description

1–26General Description

	Table 1–9	Resulting Cache Policies and ECB Status (Continued)
Cache Module Status		Cache Policy
Cache A	Cache B	Unmirrored Cache	Mirrored Cache
Less than	At least	Data loss: No.	Data loss: No.
50%	50%	Cache policy: Controller A supports	Cache policy: Both controllers continue
charged	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.
		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.