IBM Delivers iSCSI Connection, Pushes Blades to OS/400 Shops
May 15, 2006 Timothy Prickett Morgan
As it promised it would last fall, IBM has delivered an iSCSI link into the System i5 server line that will replace the special Integrated xSeries Adapter cards that it has used for a number of years to allow external xSeries X86 servers to plug into disk arrays under the skins of the iSeries and System i5 servers, using them as their primary storage. In addition to the iSCSI links, IBM announced a push to get its BladeCenter blade servers into i5 shops and various other new I/O adapter cards.
The new iSCSI adapter is based on the Internet SCSI protocol, and standard extension of the Ethernet protocol that adds SCSI disk controller protocols to it (or, if you want to be cantankerous, you can say that it is a SCSI protocol that has been modified to use Ethernet instead of copper ribbon cables and wires as a transport medium). iSCSI was invented for a number of reasons, but mostly because SCSI electronics only work when I/O devices and the servers that the SCSI controller is plugged into to are a few meters or less apart. An Ethernet link can have global distance, if you want it, and it has two other virtues: it is ubiquitous and that makes it cheap. With Gigabit Ethernet now very affordable and 10 Gigabit Ethernet building up a head of steam, Fibre Channel links between servers and storage arrays will start looking very expensive, very soon. If you want to link servers to I/O, iSCSI is the wave of the future. Particularly for cost-conscious customers, like the SMB shops that IBM is aiming the System i5 at.
According to George Gaylord, IBM’s product marketing manager for iSeries Integrated System x solutions, IBM wants to make more of its System x server line available to customers who want hybrid Power-X64 server solutions. The IxA cards were only available in fairly large IBM xSeries machines because, being a modified Fibre Channel connection (that’s what the High Speed Loop in the iSeries is and what FICON in the mainframe is, although IBM will never say it), it took up space inside the chassis. With iSCSI, IBM can put an iSCSI adapter into any xSeries or System x server, run a fiber optic or copper cable to the System i5 machine, and hook it into the appropriate copper or fiber i5 iSCSI adapter card. (Feature 5783 is the copper version of the card, while feature 5784 is the fiber version.) This iSCSI card provides block I/O support to the System i5 disk arrays, and the xSeries and System x machine has no idea it is not talking to normal SCSI disks. By the way, Gaylord says that you do not have to run an iSCSI enabled version of Windows or Linux to use these iSCSI links. The IBM cards are doing the block I/O work.
The other use for this iSCSI link is, of course, to make the Integrated xSeries Server, or IxS, co-processor no longer necessary. While a nifty gadget, the IxS card is currently limited to a 2 GHz Pentium M processor and takes up two PCI-X slots in the System i5 machine; the IxA card also took up two slots. The iSCSI card only takes up one slot. What this means is that companies that have been putting multiple IxS cards in their machines, and taking up a lot of slots in expensive I/O towers to do it, can now switch to outboard System x or BladeCenter blade servers. They can choose whatever server suits their needs or budget, and they don’t have to worry about whether or not the IxA card is supported in it.
Gaylord says that he expects a typical OS/400 shop would buy a single iSCSI adapter card and maybe handle one to three System x servers off it. “Once they get more than a handful of servers, we think customers will want to move to BladeCenters,” he says.
The iSCSI features have another neat benefit. If you set up a hybrid OS/400-Windows server, for instance, and find that the I/O is lagging between the Windows boxes and the disk arrays inside the OS/400 machine, you can simply add another iSCSI link to that machine and double the bandwidth.
The first rev of the iSCSI adapter will only support Windows Server 2003; either Service Pack 1 or Release 2 are supported. Gaylord says that IBM has Linux support for the iSCSI card in a product preview right now, which generally means that it takes about a year or less to bring it to market.
Gaylord wants everyone to also understand that IBM is not withdrawing support for the IxA or the IxS co-processor. “Customers who have already invested in the IxS and the IxA cab continue to invest in them if they choose,” he explains. “The iSCSI support just gives them options.” When pressed as to whether or not IBM would upgrade the IxS card, Gaylord gave the distinct impression that with a 21 watt thermal limit for an entire IxS card, this seemed very unlikely. Which makes sense. The future “Woodcrest” dual-core Core Xeon processors due later this summer from Intel are expected to burn about 80 watts, not counting the energy used by an external memory controller.
The iSCSI host bus adapter for the System i5 using copper links (feature 5783) costs $999, while the fiber optic version (feature 5784) costs $1,590. Both are available now. On the System x side, part number 30R5201 is the PCI-X adapter with copper wires, and part number 30R5501 is the PCI-X adapter with fiber optic links. On the BladeCenter blade servers, the part number for the iSCSI adapter is 32R1923, which supports two ports. To see a list of System x and BladeCenter gear that supports these iSCSI links, go to this IBM page.
To make the BladeCenter option more appealing, IBM has also introduced a new lower-cost Gigabit Ethernet switch that tucks into the BladeCenters, which also costs $999. This switch, which IBM calls the Server Connectivity Module, is supported on the Xeon-based HS20 blades and the Opteron-based LS20 blades. It plugs into the backplane of BladeCenter chassis and provides internal links to 14 blade servers and can provide connectivity with up to six groups of servers with dedicated uplinks. This would be a perfect switch to weave a BladeCenter without internal storage into a System i5’s disk arrays using the new iSCSI features. And that is no accident. Of course, you still have to buy iSCSI adapters for the blade servers. Still, the new GigE switch is a lot less expensive than the other BladeCenter switches, which cost $5,000 or more.
To help customers deploy BladeCenters–whether or not they are OS/400 shops–IBM has launched a “jump start service” that gives customers who shell out $6,999 a team of IBM technicians over three days who will do the transition from rack or tower servers to the BladeCenters for customers. IBM is selling this service directly and through its resellers, who are getting a $500 rebate through the end of June to push this service. (Knowing that, make resellers share with you, people.) According to Matt Wineberg worldwide product manager for the BladeCenter line, IBM is also offering more flexible lease options though Global Financing that will allow companies to get their chassis and upgrade plans in synch if they want to without having to pay hefty penalties, or allow them to get them out of synch so they can upgrade faster–again, without the typical releasing penalties.
So how have BladeCenter sales been on the iSeries to date? The complexity and cost have “definitely been a barrier to entry, but with the new connection capabilities, we expect to boost sales,” says Wineberg. “These are our accounts, and while we are asking them to make some changes, especially in places where the blade proposition resonates, without making them have to throw a lot of hardware on the floor.”
Finally, IBM has also announced faster Fibre Channel adapters for the System i5 as well as two 10 Gigabit Ethernet adapters. Feature 5758 is a single port, 4 Gbps Fibre Channel PCI-X adapter, which is used to link to storage area networks; it costs $2,646. Feature 5759 is a two-port 4 Gbps adapter, and it costs $3,308. The PCI-X 10 Gigabit Ethernet adapters are feature 5721, which provides links that can be as long as 33 meters or 300 meters using copper cable; it costs $4,742. Feature 5722 provides links as long as 10 kilometers using fiber optic links; it costs $7,999. Both 10 GigE cards only support the TCP/IP protocol; the SNA protocol is not supported.
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