IBM 201 manual Storage configuration, ServeRAID configuration, RAID technology

Chapter 4. Storage configuration

This chapter gives the details for setting up and configuring the NAS 200 storage.

ServeRAID configuration

This section gives details on configuring the ServeRAID adapter.

RAID technology

RAID technology allows you to group several physical drives into an array that you can define as one or more logical drives. Each logical drive appears to the operating system as a single drive. This grouping technique greatly enhances logical-drive capacity and performance beyond the physical limitations of a single physical drive.

For an overview of RAID technology, see Chapter 3 ″Understanding RAID technology″ in the ServeRAID-4x Ultra160 SCSI Controller publication, which is included on the Documentation CD that came with your appliance.

Table 2 shows the standard features of the ServeRAID-4Lx and ServeRAID-4H.

Table 2. Standard features of ServeRAID-4Lx and ServeRAID-4H

Feature	ServeRAID-4Lx (Model 201)	ServeRAID-4H (Model 226)
Arrays (maximum)	8	8
Battery-backup cache	No	Yes
Cache memory	16 MB	128 MB
Logical drives (maximum)	8	8
SCSI channels	1	4
SCSI transfer speed	160 MB/sec	160 MB/sec
(maximum)
Supported RAID levels	0, 1, 5, Enhanced-1 (1E),	0, 1, 5, Enhanced-1 (1E) and
	and Enhanced-5 (E5), 00, 10,	Enhanced-5 (E5), 00, 10,
	1E0, 50	1E0, 50
System PCI data bus	64–bit at 33 MHz	64–bit at 33 MHz

Updating the ServeRAID BIOS, firmware, and device drivers

The NAS 200 preloaded software ships with the required BIOS, firmware and device drivers. You do not need to load or update any of these items. Should replacement software be required, it will be available online as described in the Storage Unit Installation and User’s Guide GA27-4259.

Attention: Because the NAS 200 hardware and software is preconfigured as a high-performance network-attached storage appliance, you should not update the BIOS, firmware, or device drivers using the procedures described in the ServeRAID-4x Ultra160 SCSI Controller publication.

Functionality not needed and not supported in the NAS 200

Because the ServeRAID hardware and software is used in several IBM products, note that the ServeRAID-4x Ultra160 SCSI Controller publication refers to the following items that are not applicable and not supported on the NAS 200:

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