LSI MegaRAID SCSI 320-2 RAID Controller Series 518 - Manual (Page 67)

Creating Logical Drives 5-11
Copyright © 2002 by LSI Logic Corporation. All rights reserved.
assumed. Table 5.4 describes the RAID levels, including the number of
drives required, and the capacity.
5.3.1.2 Maximizing Drive Availability
You can maximize the availability of data on the physical disk drive in the
logical array by maximizing the level of fault tolerance.
Table 5.5
describes the levels of fault tolerance for the RAID levels.
Table 5.4 Capacity for RAID Levels
RAID
Level Description
Drives
Required
Capacity
0 Striping
without parity 1 – 30 (Number of disks) X capacity of
smallest disk
1 Mirroring 2 (Capacity of smallest disk) X (1)
5 Striping with
floating parity
drive 3 – 30 (Number of disks) X (capacity of
smallest disk) - (capacity of 1 disk)
10 Mirroring and
Striping 4 – 30
(Must be a
multiple of 2.) (Number of disks) X (capacity of
smallest disk) / (2)
50 RAID 5 and
Striping 6 – 30 (Must
be a multiple
of the # of
arrays.) (Number of disks) X (capacity of
smallest disk) – (capacity of 1 disk X
number of arrays)
Table 5.5 Fault Tolerance for RAID Levels
RAID Level Fault Tolerance Protection
0 No fault tolerance.
1 100% protection through data mirroring.
5 100% protection through striping and parity. The data is striped
and parity data is written across a number of physical disk
drives.
10 100% protection through data mirroring.
50 100% protection through data striping and parity. All data is
striped and parity data is written across all drives in two or
more arrays.