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1.
How many physical SCSI hard disks are to be integrated in the Array Drive ?
2.
Which redundancy level ought to be achieved ?
3.
Should RAIDYNE automatically recover redundancy in the event of a disk
failure ? Or, in other terms: Are Hot Fix drives needed ?
Before we go through these examples step by step, we would like to explain a few terms and
relations important for the basic understanding of the ICP Controller firmware. At the end of
example 4, we will try to answer the three questions above.
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We refer to firmware as the operating system which controls the ICP Controller with all its
functions and capabilities. The firmware exclusively runs on the ICP Controller and is stored
in the Flash-RAM on the ICP Controller PCB. The controlling function is entirely independ-
ent of the PCI computer and the host operating system installed (for example UNIX), and
does not "drain" any computing power or time from the PCI computer. According to the
performance requirements needed, the ICP Controllers are available with two firmware vari-
ants. The firmware is either already installed on the controller upon delivery, or can be
added as an upgrade:
RAIDYNE upgrade
.
Standard Firmware
(installed on the GDT6
1
xyRP controllers).
In addition to simple controlling functions regarding SCSI hard disks or removable
hard disks, this version allows disk chaining (several drives can be linked in order to
form a single "large" drive), and the configuration of Array Drives of the types data
striping (RAID 0) and disk mirroring or duplexing (RAID 1).
RAIDYNE Firmware
(installed on the GDT6
5
xyRP controllers). In addition to disk
chaining, RAID 0 and RAID 1, RAIDYNE allows you to install and control Array
Drives of the types RAID 4 (data striping with dedicated parity drive), RAID 5 (data
striping with
distributed parity) and RAID10 (a combination between RAID 0 and 1)
RAIDYNE is the name of the ICP disk-array operating system for the ICP Controllers. Unlike
pure software solutions, RAIDYNE is totally independent of the host operating system, and
can therefore be accessed under MS-DOS, Windows, OS/2, SCO-UNIX, Interactive UNIX,
Novell NetWare, etc.. Special RAID drivers are not needed. The integration of a RAID Disk
Array into the host operating system is carried out with the same drivers used for the inte-
gration of a single SCSI hard disk. All ICP Controllers are equipped with a hardware which is
particularly well suited for disk arrays. RAIDYNE uses this hardware with extreme efficiency
and therefore allows you to configure disk arrays that do not load the host computer
(whereas all software-based RAID solutions more or less reduce the overall performance of
the host computer.).
The basic concept of the RAIDYNE is strictly modular, and consequently, in
its functioning it appears to the user as a unit construction system.
