Capacity Expansion - Compaq N2400 - TaskSmart - 1 GB RAM Administration Manual

Capacity Expansion

The TaskSmart N2400 appliance is designed for expansion. You can add up to
four external storage enclosures to the system for a total of 56 external data
drives. Depending on your needs, many configuration options are available:
Add new drives to an existing array, and create a new logical drive or
drives
Add new drives, create a new array, and create a new logical drive or
drives
Add the new logical drive or drives to existing pool or pools
Create a new pool or pools using the new logical drive or drives
Use new pool space to expand existing virtual disks
Use new pool space or new pools to create new virtual disks
These options give the administrator great flexibility in adding new storage
space or effectively expanding existing space. If you add space to an existing
pool, the virtual disks created in that pool can be expanded, or new virtual
disks can be created to take advantage of the space. Use the procedures
described in the previous sections for creating arrays, logical drives, pools, and
virtual disks.
When you plan for adding space to your appliance, consider the following:
Add drives in groups of three or four. Because new drives must be
configured as new logical drives, and RAID 5 sets must have at least
three members, for best performance add drives in sets of at least three,
and preferably seven or more. Sets of 14 reduce the drive space lost to
RAID 5 overhead or parity.
The maximum number of storage units (logical drives) in a pool is eight.
If you want to have large pools from which to create virtual disks, it is
advantageous to make logical drives as large as possible.
Each array that you create must have at least one online spare drive. The
same online spare drive can be assigned to multiple arrays, but it must
be replaced with a new spare if the existing spare is used. The original
online spare drive remains a part of the array until the replacement drive
is installed.
Advanced Administrative Procedures 6-35