Adaptec RAID 2100S Software User's Manual page 65

The array expansion feature enables you to add the new drives to
the array while the system is active and users are logged in and
accessing data. After the array is expanded, use the Windows Disk
Administrator to add the additional space to the volume set of the
array, then shutdown the system and restart. When the system
restarts, Windows recognizes the additional space as part of the
existing logical drive.
Note: Array expansion significantly reduces overall system
performance. To mitigate the impact, adjust the relative
priorities of processes in Storage Manager by setting the
Background Task Priority (see
Array expansion maintains the performance gains of RAID 0 and
RAID 5, spreading accesses randomly across the drives in the array.
The controller presents the same number of LSUs to the operating
system after the expansion. There is no need for manual load
balancing, which would be required if the new space were presented
as an additional LSU.
Requirements and Restrictions
Array expansion has the following system requirements and
restrictions.
Windows 2000, Windows NT 4.0, Server or Workstation, with
the most recent service pack.
Adaptec OSM only. (The Microsoft OSM does not support array
expansion.)
RAID 0 or RAID 5 array groups only
NTFS file system only. (You cannot extend a volume that has a
FAT partition. Instead, you would add the extra space as a
separate LSU.)
You cannot extend the Windows NT or Windows 2000 boot
partition.
The array must have Optimal status before beginning the
expansion. If the array status is not Optimal, correct the
problem and complete a rebuild of the existing array before
continuing with expansion.
page 3-48).
Storage Manager
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