Using Microsoft Cluster - Compaq ProLiant 1600 Administrator's Manual

2-30 Compaq ProLiant Clusters HA/F100 and HA/F200 Administrator Guide
For example, the Web Sales Order Database group depends on a log file, data
files, and program files. It might be important for the log file and program files
to have a quick recovery time, while performance would be a secondary
concern. Together, the files do not take up much capacity; therefore, mirroring
(RAID 1) would be an efficient use of disk space and would fulfill the
recovery and performance characteristics. The data files, however, would need
excellent performance and excellent protection. The data files are expected to
be large; therefore, a mirrored configuration would require an unacceptably
expensive number of disk drives. To minimize the amount of physical capacity
and still meet the performance and protection requirements, the data files
would be configured to use Distributed Data Guarding (RAID 5).
Array Configuration
The Compaq Array Configuration Utility (ACU) is used to initially configure
the array controller, reconfigure the array controller, add additional disk drives
to an existing configuration, and expand capacity. The capacity expansion
feature provides the ability to add storage capacity to a configured array
without disturbing the existing data and to add a new physical drive to the
array.
An array is created by grouping disk drives together to share a common
RAID (Redundant Array of Inexpensive Disks) fault tolerance type. For
example, in a single RA4000 storage system containing eight 18.2 GB drives,
you could configure two of the drives in a RAID 1 mirrored array and the
remaining six drives as a RAID 5 Distributed Data Guarding array.
Each array must be divided into at least one volume (up to a maximum of
eight volumes per array). Each volume is presented to the operating system as
an independent disk drive and can be independently controlled by the cluster
software. Using the previous example, you could configure the two-drive
RAID 1 array as a single volume (for example, drive F), and the six-drive
RAID 5 array as two volumes (for example, drives G and H). Because the
operating system views these as independent disks, it is possible for cluster
Node1 to control drive G, while cluster Node2 controls drives F and H.
More information regarding cluster disk configuration can be found in the
Compaq TechNote, Planning Considerations for Compaq ProLiant Clusters
Using Microsoft Cluster Server, located on the Compaq website
(
http://www.compaq.com).
This capability provides a high level of flexibility in configuring your RA4000
storage system. However, minimize the number of volumes configured in each
array to improve performance. To achieve optimal performance, each array
should contain a single volume. In some cases (such as for the MSCS quorum
drive), it may be desirable to add a second, smaller volume to an array.