Chapter 2. Architecture and technical overview
21
transfer of data between storage and servers in block I/O formats (defined by iSCSI protocol)
and thus enables the creation of IP SANs. iSCSI allows an existing network to transfer SCSI
commands and data with full location independence and defines the rules and processes to
accomplish the communication. The iSCSI protocol is defined in iSCSI IETF draft-20. For
more information about this standard, see:
http://tools.ietf.org/html/rfc3720
New iSCSI adapters for IBM System p5 systems provide the advantage of increased
bandwidth through the hardware support of iSCSI protocol. The 1 Gigabit iSCSI TOE PCI-X
adapters support hardware encapsulation of SCSI commands and data into TCP and
transports over the Ethernet using IP packets. The adapter operates as an iSCSI TOE
(TCP/IP Offload Engine). This offload function eliminates host protocol processing and
reduces CPU interrupts. Adapter uses Small form factor LC type fiber optic connector or
copper RJ45 connector. Table 2-5 provides the orderable iSCSI adapters.
Table 2-5 Available iSCSI adapters
IBM iSCSI software Host Support Kit
The iSCSI protocol can also be used over standard Gigabit Ethernet adapters. To use this
approach, download the appropriate iSCSI Host Support Kit for your operating system from
the IBM NAS support Web site:
http://www.ibm.com/storage/support/nas/
The iSCSI Host Support Kit on AIX 5L and Linux® acts as a software iSCSI initiator and
allows access to iSCSI target storage devices using standard Gigabit Ethernet network
adapters. To ensure the best performance enable the TCP Large Send, TCP send and
receive flow control, and Jumbo Frame features of the Gigabit Ethernet Adapter and the
iSCSI Target, tune network options and interface parameters for maximum iSCSI I/O
throughput on the operating system.
2.4.8 Fibre Channel adapters
The IntelliStation POWER 285 supports direct or SAN connection to devices using Fibre
Channel adapters. Single-port Fibre Channel adapters are available in 2-Gbps and 4-Gbps
speeds. A dual-port 4-Gbps Fibre Channel adapter is also available. Table 2-6 on page 22
provides a summary of the available Fibre Channel adapters.
All of these adapters have LC connectors. If you are attaching a device or switch with an SC
type fiber connector an LC-SC 50 Micron Fiber Converter Cable (FC 2456) or an LC-SC 62.5
Micron Fiber Converter Cable (FC 2459) is required.
Supported data rates between the server and the attached device or switch are as follows:
Distances of up to 500 meters running at 1 Gbps, distances up to 300 meters running at 2
Gbps data rate, and distances up to 150 meters running at 4 Gbps. When these adapters are
used with IBM supported Fibre Channel storage switches supporting long-wave optics,
distances of up to 10 kilometers are capable running at either 1 Gbps, 2 Gbps, or 4 Gbps data
rates.
Feature code
Description
Slot
Size
Max
1986
Gigabit iSCSI TOE PCI-X on copper media adapter
64
short
3
1987
Gigabit iSCSI TOE PCI-X on optical media adapter
64
short
3
