HSG80 ACS Solution Software Version 8.7 for Compaq Tru64 UNIX Installation and Configuration Guide

Glossary
Glossary–24 HSG80 ACS Solution Software Version 8.7 for Compaq Tru64 UNIX Installation and
Configuration Guide
write hole
The period of time in a RAID level 1 or RAID level 5 write operation
when an opportunity emerges for undetectable RAIDset data
corruption. Write holes occur under conditions such as power outages,
where the writing of multiple members can be abruptly interrupted. A
battery backed-up cache design eliminates the write hole because data
is preserved in cache and unsuccessful write operations can be retried.
write-through
cache
A cache management technique for retaining host write requests in
read cache. When 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 may update, invalidate, or delete data
from the cache memory accordingly, to ensure that the cache contains
the most current data.