Last Tuesday, IBM unveiled new storage offerings that will enable iSeries users to improve the availability of their servers. At the same time, the company discussed impending changes to the iSeries family that will affect the buying decisions of many companies.

On the product front, IBM announced two enhanced disk controllers that provide higher levels of storage protection for RAID-5 disk arrays than current controllers. To create the products, IBM took its existing 2780 and 2757 RAID disk controllers and added an auxiliary 757 MB write cache that resides on a separate adapter card. If the disk controller fails, the auxiliary write cache maintains the contents of the controller's write cache in memory. This significantly reduces the time that it takes to reinitialize an iSeries and recover its disk arrays. Improving such times is especially important when using the 2780/2757 controllers because their large caches improve disk performance but also increase the time needed to recover cached data.

To make the enhanced controllers attractive to customers, IBM is offering them at reasonable prices. While standard 2780 and 2757 RAID controllers cost $7,200, the enhanced versions with the auxiliary write cache--known as the 5580 and 5581, respectively--cost $7,995. That is only an 11% premium over the original controllers. Customers can also upgrade their existing 2780/2757 controllers to the 5580/5581 at a cost of $2,995. That price is not as attractive, but some companies may consider it a value in the light of their availability requirements.

While the 5580 and 5581 have fairly attractive prices, customers need to know that their auxiliary write caches attach to the fourth port on the 2780/2757 controllers. This means that customers can populate the enhanced controllers with only 15 disk drives versus the 20 drives supported on the original 2780/2757 controllers. As such, iSeries owners that are running more than 15 drives per array may require more controllers than they do at present. In addition, the auxiliary write cache takes up another I/O processor (IOP) slot, so customers must have enough slots to accommodate the extra adapter cards. These requirements could increase the cost of providing write cache protection for some customers.

The 5580 and 5581 will begin shipping on May 27 of this year and are supported by all iSeries 270 and 8xx models as well as the eServer i5. Customers must use OS/400 V5R2 or V5R3 to support the controllers. They must also install a PTF to enable 5580/5581 support. While the PTF for V5R3 will become available on May 27, V5R2 users will need to wait until July to get their PTF. IBM will probably announce the exact shipment date in a few weeks.

While IBM is beefing up its RAID-5 offerings with the 5580 and 5581, it continues to promote mirrored storage as the best high-availability solution. Moreover, it is making mirrored storage systems increasingly attractive on a cost-per-GB basis. In keeping with that trend, the company announced four new mirrored storage packages for its eServer i5 models last Tuesday. Each package includes an I/O tower or drawer, one IOP, two 2757 controllers, and 12 disks with either 35 GB or 70 GB of capacity per drive. This creates a storage subsystem with six mirrored drives and a single mirrored controller. The two packages with 35 GB drives cost $29,900; the other two packages with 70 GB drives carry a $35,900 sticker. At these price levels, the packages cost roughly the same as RAID-5 arrays that contain seven 35 GB or 70 GB drives. In other words, customers can create mirrored disk arrays with the new packages that cost only about 17% more per GB than equivalent RAID-5 arrays. Those economics could lead many customers to pick mirroring over RAID-5 for at least some of their data.

The four new mirroring packages--known as feature codes 5560, 5561, 5562, and 5563--will ship on April 29 for all eServer i5 customers. If you need a discounted mirroring package for an iSeries 8xx model, your best options are the feature codes 5554 and 5555 that IBM announced late last year. Like the new packages, the 5554 and 5555 provide an array of 12 drives with either 35 GB or 70 GB of capacity.

A Swan Song for the iSeries 8xx

While I will not try to sing "Time to Say Goodbye" like Andrea Bocelli (you would all hoot me off the stage), IBM did use last Tuesday to announce that it will no longer sell any iSeries 8xx models as of October 1, 2005. To be specific, this is the date when IBM will cease to sell any new iSeries Model 810, 825, 870, or 890 servers. On the same day, the company will cease to sell any upgrades between these models, such as from the Model 825 to the 870. Owners of these systems will still be able to upgrade within their current model numbers, such as from a Model 810 with 750 CPW of performance to one with 1,470 CPW. They will also be able to upgrade to eServer i5 models. However, if IBM runs true to form, it will withdraw these remaining upgrade options over the next two years. The company will probably withdraw upgrades within the iSeries 8xx models in late 2006 and then withdraw upgrades from these models to the eServer i5 in late 2007.

While these marketing withdrawals may affect the hardware plans of many companies, they are not the only withdrawals that iSeries customers need to consider. In a future article, I will delve into some additional statements IBM made last Tuesday that could affect the IT decisions that you make over the next several years. Next week, however, I will be studying several other breaking news items from IBM, so stay tuned.

Lee Kroon is a Senior Industry Analyst for Andrews Consulting Group, a firm that helps mid-sized companies manage business transformation through technology. You can reach him at This email address is being protected from spambots. You need JavaScript enabled to view it..

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Lee Kroon is a Senior Industry Analyst for Andrews Consulting Group, a firm that helps mid-sized companies manage business transformation through technology.