Intel SRCU32 - RAID Controller, User Manual

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18 Intel RAID Controller SRCU32 User’s Guide
Levels of Drive Hierarchy Within the Intel
®
RAID
Controller SRCU32 Firmware
The Intel
®
RAID Controller SRCU32 firmware is based on four fundamental levels of hierarchy.
Each level has its own drives (components). The basic rule is to build up a drive on a given level of
hierarchy. The drives of the next lower level of hierarchy are used as components.
Level 1
Physical drives are hard drives and removable hard drives. Some Magneto Optical (MO) drives are
located on the lowest level. Physical drives are the basic components of all “drive constructions.”
However, before they can be used by the firmware, these hard drives must be “prepared” through a
procedure called initialization. During this initialization each hard drive receives information,
which allows an univocal identification even if the SCSI ID or the controller is changed. For
reasons of data coherency, this information is extremely important for any drive construction
consisting of more than one physical drive.
Level 2
On the next higher level are the logical drives. Logical drives are introduced to obtain full
independence of the physical coordinates of a physical device. This is necessary to easily change
the Intel RAID Controller SRCU32 and the channels, IDs, without loosing the data and the
information on a specific disk array.
Level 3
On this level of hierarchy, the firmware forms the array drives. Depending on the firmware
installed an array drive can be:
•
Single Disks: one disk or a JBOD (just a bunch of drives)
•
Chaining sets (concatenation of several hard drives)
•
RAID 0 array drives
•
RAID 1 array drives, RAID 1 array drives plus a hot fix drive
•
RAID 4 array drives, RAID 4 array drives plus a hot fix drive
•
RAID 5 array drives, RAID 5 array drives plus a hot fix drive
•
RAID 10 array drives, RAID 10 array drives plus a hot fix drive