System information

32 Chapter 3
Adjusting LUN Masking
See “Masking Drives on Multiple Host Systems (LUN Masking)” on page 21 for details on
LUN masking for systems that are connected to a switch and have multiple hosts connected
to the switch.
Adjusting Drive Cache and Controller Cache
RAID Admin lets you turn on two separate types of cache to enhance performance of your
Xserve RAID system.
m Drive cache enables the built-in write cache on each drive in the array. This option
improves efficiency and speed of data transfer, but the drive cache is not backed up
should the system lose power unless you are using an uninterruptible power supply
(UPS).
m Controller cache is a write cache used by the RAID controller. This cache is backed up by
the optional Xserve RAID Cache Backup Battery Modules.
To set up drive cache and controller cache:
1 Open RAID Admin and click Settings.
2 Enter the management password and click OK.
Important It is recommended that you use a UPS when you have drive cache enabled.
Without UPS backup, you could lose data in the event of a power failure.
Important It is recommended that you have the optional controller cache backup
battery modules installed if you use controller cache. Using controller cache with no
battery backup could result in data loss if there is a power failure.