Intel SRCMR, User Manual

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18 Intel RAID Controller SRCMR User’s Guide
Levels of Drive Hierarchy Within the Intel RAID Controller
SRCMR Firmware
The Intel RAID Controller SRCMR 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 disks and removable hard disks. 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 disks must be “prepared” through a
procedure called initialization. During this initialization each hard disk 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 SRCMR 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 disks)
•
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