Chapter 7. IBM iSeries 820, 830, and 840 features and placement 287
#2782 #2782 PCI-X RAID Disk Unit Controller
The #2782 is a PCI-X SCSI controller with a 40 MB cache that provides RAID-5 protection for internal disks and also
supports internal tape units, CD-ROM and DVD devices. #2782 has two SCSI buses that support up to 12 disk units.
Hardware data compression is not supported.
In addition to providing RAID-5 protection for disks, #2782 also works as a high-performance controller for disks protected
by system mirroring, or disks with no protection. In the RAID-5 configuration, disk unit protection is provided at less cost
than mirroring, and with better performance than system checksums.
A minimum of three disk units of the same capacity are needed for a valid RAID-5 configuration. A maximum of four arrays
are allowed per controller, with a maximum of 12 disk units allowed per array. All disk units in an array must be of the same
capacity.
Parity is spread across either two, four, or eight disk units in an array. If an array of three disk units is started, parity is spread
across two disk units. If an array of four to seven disk units is started, parity is spread across four disk units. If an array of
eight to 12 disk units is started, parity is spread across eight disk units.
The number of arrays and size of each array can be influenced by specifying an optimization of either Balance,
Performance, or Capacity when starting arrays in iSeries Navigator. An optimization of Balance is used by default when
starting arrays from the DST or SST options. If disk units are included into an existing array, parity can be spread across
less than the preferred number of disk units. In this case the RAID function must be stopped and then started in order to
redistribute the parity.
The #2782 controls up to two removable media devices (internal tape, CD-ROM and DVD).
The #2782 PCI-X RAID Disk Unit Controller does not support hardware data compression.
The #2782 does not support the attachment of external devices.
Minimum operating system level: OS/400 V5R2
The #2782 is a Customer Install Feature.
The #2782 was withdrawn from marketing on 01 January 2004. The recommended replacement is a #5703 PCI-X RAID
Disk Unit Controller.
#2787 #2787 PCI-X Fibre Channel Disk Controller
The #2787 PCI-X Fibre Channel Disk Controller provides Fibre Channel attachment capability for external disk devices.
The #2787 supports point-to-point and arbitrated loop topologies and has an LC-type cable connector. Each #2787 is
shipped with a wrap connector (part number 05N6767). It supports 64-bit, 133MHz PCI-X bus speeds. It is the PCI-X
replacement card for the #2766 PCI Fibre Channel Disk Controller.
The following adapter kits are required when connecting SC-type cables to the #2787:
#0371 - LC-SC Adapter Kit (50um) can be ordered, both on initial, model upgrades, and simple MES orders. This
optional kit is used to attach SC-type fibre (50 micron) cables to a #2787. The #0371 kit contains a 2 m LC-ST cable
and ST-SC adapter for 50 micron fiber cable.
#0372 - LC-SC Adapter Kit (62.5um) can be ordered, both on initial, model upgrades, and simple MES orders. This
optional kit is used to attach SC-type fiber (62.5 micron) cables to a #2787. The #0372 kit contains a 2 m LC-ST cable
and ST-SC adapter for 62.5 micron fiber cable.
An optics cleaning kit (part number 46G6844) and instruction sheet (part number 21P6238, form number SY27-2604) is
supplied, one per system, when a #2787 is ordered.
When used as a Direct Attached Adapter for Linux, the #0626 should be ordered in place of the #2787.
Maximum physical quantities are determined by requiring a dedicated IOP and limited to two per Multi-adapter Bridge
boundary.
All Fibre Channel cables required for the #2787 PCI-X Fibre Channel Disk Controller are supplied by the client.
Minimum operating system level: OS/400 V5R2
The #2787 is a Customer Install Feature
