Online Capacity Expansion; Hard Drive Upgrades - Compaq RAID Array 4100 User Manual

E-16 Compaq StorageWorks RAID Array 4100 User Guide

Online Capacity Expansion

Hard Drive Upgrades

It is important to remember that all physical drives in an array should be the
same size (capacity). This is because each drive contains an equal portion of
one or more logical drives and the portion sizes can only total the size of the
smallest drive. While you are not prevented from expanding storage capacity
with larger drives, the extra space cannot be used.
During expansion of an array that initially has two or more logical drives, the
redistribution of data takes place one logical drive at a time. When the capacity
expansion has completed, any newly created logical drive will become
available.
In certain cases, the RA4000 Controller and Array Configuration Utility also
support making storage capacity changes online. These cases are:
I
Windows NT or NetWare operating system (NetWare 3.11 not
supported)
I
Hot-pluggable drives
Because the Array Configuration Utility reconfigures the RA4000 Controller,
online reconfiguration can only take place if Array Configuration Utility is
running in the same environment as the normal server applications. The Array
Configuration Utility is available in versions for Windows NT or NetWare.
Additional storage space can be obtained with the same number of physical
drives in a fault-tolerant configuration by replacing these drives with others of
higher capacity. By replacing the drives one at a time, the data on the new
drive is recreated from redundant information on the remaining drives. After
each new drive has been rebuilt, the next can be replaced. After all drives have
been replaced and rebuilt, the additional capacity on each drive can be utilized
by adding a new logical drive. The Array Configuration Utility will
automatically recognize the unused space and guide you through the
procedures to make use of it.