RAID Technology
Hard Disk Drive Capacities
With a server, it is important to understand the implications of hard
disk drive capacities and how they influence the way you create
disk arrays.
Although the drives in the disk array can be of different capacities
(for example, 1 GB or 2 GB), they are treated in the disk array
configuration as if they all have the capacity of the smallest disk
drive. Therefore, if you have four drives of 1 GB, 1 GB, 1 GB, and
2 GB grouped in one disk array, the total capacity of the array is
1 GB times 4, or 4 GB (instead of the 5 GB physically available).
Notes:
1. The total capacity of the array without protection would
be 4 GB. With RAID level 5, the usable data capacity
would be 3 GB.
2. 1 GB is approximately 1 000 000 000 bytes.
Additional Storage Capacity
With the Administration and Monitoring program Remote Monitor,
you can dynamically add capacity to your server by defining
additional arrays and logical drives (when your operating system
supports this). When you use the Remote Monitor, you do not have
to restart the server to create an array.
When you add hard disk drives to your server, you must configure
a new disk array before you can use the drives. You can either
reconfigure the existing disk array to include the capacity offered
with the added drives, or group the added drives into their own
array (see “Creating a Disk Array” on page 85). You also can create
an array with only one drive.
The ServeRAID Configuration Program Screens
When you configure your disk array, or even just view its
configuration, you will be using the IBM ServeRAID configuration
program on the IBM PC ServeRAID Adapter Configuration Diskette
(also called the ServeRAID Adapter Configuration Diskette). The
following figure is a compilation of many of the IBM ServeRAID
Chapter 3. Configuring the Disk Array
77
Summary of Contents for PC Server 520
Page 1: ...PC Server 520 User s Handbook for PCI Micro Channel IBM...
Page 86: ...Installation Checklist 70 PC Server 520 User s Handbook for PCI Micro Channel...
Page 146: ...Using the Mini Configuration Program 130 PC Server 520 User s Handbook for PCI Micro Channel...
Page 190: ...Using the SCSISelect Utility Program 174 PC Server 520 User s Handbook for PCI Micro Channel...
Page 385: ...Installing Additional Test Programs 207 CMD 3 Chapter 7 Solving Problems 369...
Page 438: ...IBM Part Number 78H6336 Printed in U S A May 1996 78H6336...
