HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software Command Line Interface Reference Guide (EK-G80CL-RA. C01, March 2005)

Glossary
337HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software
Command Line Interface Reference Guide
writeback caching
A cache management method used to decrease the subsystem’s response time to write
requests by allowing the controller to declare the write operation “complete” as soon as the
data reaches its cache memory. The controller performs the slower operation of writing the
data to the disk drives at a later time.
write-through cache
A cache management technique for retaining host write requests in read cache. the host
requests a write operation, the controller writes data directly to the storage device. This
technique allows the controller to complete some read requests from the cache, greatly
improving the response time to retrieve data. The operation is complete only after the data
to be written is received by the target storage device.
This cache management method can update, invalidate, or delete data from the cache
memory accordingly, to ensure that the cache contains the most current data.
write-through caching
A cache management method used to decrease the subsystem’s response time to a read.
This method allows the controller to satisfy the request from the cache memory rather than
from the disk drives.