Avago Technologies LSI SAS 3041E-R - Manual (Page 135)

Setup Utility Menu Screens 7-15
Version 1.3 Copyright © 2001, 2002, 2007 by LSI Logic Corporation. All rights reserved.
7.3.7.1 Array Types
You can use the SCSI BIOS Setup utility to create either mirrored arrays
or striped arrays, depending on which type of array the BIOS supports.
Mirrored arrays protect against data loss by maintaining two copies of the
data. Striped arrays provide faster data I/O but do not protect against
data loss. Here are brief descriptions of the array types:
•
Integrated Mirroring (IM) arrays are simple sector-to-sector physical
mirrors of one drive to another drive. Two disk drives are used for IM
arrays. An optional hot spare disk can also be added.
•
RAID 1E arrays use a striped layout in which each stripe unit has a
secondary copy stored on a different disk. Three to six disk drives
are used for this type of array. (The maximum is five disk drives if a
hot spare disk is also defined.)
•
Integrated Striping (IS) arrays write data across multiple disks
instead of onto one disk. This is accomplished by partitioning each
disk’s storage space into stripes. The stripes are interleaved round-
robin across all disks in the array, so that the combined storage
space is composed alternately of stripes from each disk. As a result,
data can be retrieved faster.
To create a new IM array that mirrors the data already present on one
disk drive, select the disk with the data as the first (primary) disk in the
array. When you select the first disk, the setup utility prompts you to
either Keep Data or Erase Disk. Press F3 to keep the existing data. If
you are creating a RAID 1E array you cannot keep existing data to mirror.
All existing data is erased from all the array disks.
When you have finished with this menu, press Esc. If you made
changes, such as defining a new array, you will be given the choice of
saving or discarding the configuration. When you select Save the new
array will be created.
7.3.7.2 Creating RAID Arrays
This section explains how to use the SCSI BIOS Setup utility to create
RAID arrays. The first subsection explains how to create mirrored (IM
and RAID 1E) arrays. The second subsection explains how to create
striped (IS) arrays. The version of the BIOS determines which kind of