D-18
Understanding Drive Arrays
Writer: Pamela King Project: SMART-2DH Array Controller Reference Guide Comments: 295469-002
File Name: K-APPD.DOC Last Saved On: 2/27/98 12:06 PM
COMPAQ CONFIDENTIAL - NEED TO KNOW REQUIRED
Daz-9-14.EPS
Original
Logical
Drive
Added
Physical
Drives
Data from original logical drive redistributed over "Top" of all
physical drives.
New logical drive created over "Bottom" of all physical drives.
D-11.
Expanded array storage capacity with a second logical drive
Example:
Assume you have two ProLiant Storage Systems with a total of 10
drives and you want to expand this to the 14-drive maximum supported by one
SMART-2DH Controller. With Array Configuration Utility running, simply
install four matching drives in the empty drive bays. At this point your array
will resemble Figure D-10, with the original data (original logical drive)
represented by the gray shaded drives and the new drives unshaded. Execute
the Array Configuration Utility, which is located on the Compaq SmartStart
and Support Software CD, to start the expansion process as described in
Chapter 5.
The SMART-2DH Controller will then redistribute the data to an equal
portion of all the drives, using the same fault tolerance method used
originally. This is still the first logical drive, but it now spans 14 drives
instead of 10. Array Configuration Utility also detects the unused space on
each drive (because each drive contains 10/14ths of the data that it used to)
and helps you configure it into a second logical drive with its own fault
tolerance, distributed over the extra space of all the drives.
When this process is finished both logical drives, one containing the original
data and the new empty one, will be configured into a single array with more
total capacity than the original one. Now your array will look more like Figure
D-11, using the same shading scheme to represent the logical drives.