User Manual

Software ROMB User Manual
108
Read Cache Setting
There are two read cache settings. You make this setting when you create a
logical drive or under logical drive settings.
• Read Cache – The read cache is enabled.
• Read Ahead Cache – Enables the read cache and the read-ahead feature.
Read-ahead anticipates the next read and performs it before the request is
made. Can increase read performance.
• No Cache – The read cache is disabled.
Write Cache Setting
There are two write cache settings. You make this setting when you create a
logical drive or under logical drive settings.
• Write Back – Data is written first to the cache, then to the logical drive.
Better performance. Requires a cache backup battery to protect data in the
cache from a sudden power failure.
• Write Through – Data is written to the cache and the logical drive at the
same time. Safer.
Logical Drive Migration
To migrate a logical drive is to:
• Change its RAID level
• Add one or more physical drives
• Both of the above actions
You must use WebPAM to perform a migration. See “Migrating a Logical Drive”
on page 80.
To migrate a logical drive, its operational status must be Functional.
The Software ROMB supports the following logical drive migration source and
target configurations: