IBM i Series, Handbook

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I/O Adapters and Controllers
304
iSeries Handbook
The #4748/#9748 controller supports a maximum of 18 drives. A minimum of four drives of
the same capacity are needed for a valid RAID-5 configuration. A maximum of four arrays are
allowed, with a maximum of ten drives allowed per array. All drives in an array must be of the
same capacity.
The #4748/#9748 also supports two removable media devices. This feature supports the
#4331 1.6 Gb Read Cache Drive for increased performance. The Read Cache Drive #4331 is
only supported in non-compression mode.
The #4748 feature is hot pluggable.
The #4748 is supported in all 8xx processors and the Model 270.
#9767 PCI Disk Unit Controller
The #9767 is an Ultra2 SCSI disk unit and removable media device controller.
The #9767 is the default controller in the Model 270 and controls up to six disk units and up to
two removable media devices (internal tape or CD-ROM/DVD-RAM).
The #9767 is the default controller in the Model 820 when RAID (#0041 Device Parity
Protection-All) is not on the order and controls up to six disk units on the pre-V5R1processors
and up to four disk units on the new V5R1 processors. Up to two removable media devices
(internal tape or CD-ROM/DVD-RAM) are also supported.
In the #5075 PCI Expansion Tower, the #9767 supports up to four disk units.
#2749 PCI Ultra Magnetic Media Controller
The #2749 is an Ultra SCSI controller for attachment of an external tape device or an external
optical device.
When attaching Ultra SCSI to a #2749, the instantaneous data transfer rate is 40 MB/sec,
and the sustained rate is 38 MB/sec.
The #2749 feature is hot pluggable.