AdStar extends System Managed Storage

Electronic News, May 25, 1992 by Gerry Khermouch

TUCSON, ARIZ.--In its first major roll-out as an autonomous division, IBM's AdStar storage systems unit extended its system Managed Storage approach beyond disks to encompass both tape and optical media, and to support heterogeneous networks of PCs and workstations.

The enhancements to the Data Facility Storage Management Subsystem (DFSMS) spell SMS' "coming of age," according to AdStar general manager Ray AbuZayyad, and will play a major role in enabling customers to mix a wide variety of storage media to support their enterprise, rather than relying on any single solution. Most functions will be available by next March.

In addition to broadening DFSMS to include tape and optical media, the new version will enhance disk storage management by adding such features as concurrent copy and sequential data striping. The concurrent copy function acts as a "snapshot" type of backup that does not require the system to be taken down, while sequential data striping improves I/O performance by allowing data to be distributed among as many as 16 of IBM's 3390 drives.

A new Data Facility Distributed Storage Manager (DFDSM) program allows systems running IBM's MVS or VM operating systems to act as servers to PC and workstation networks, including machines from Apple, Sun and IBM's PS/2 and RS/6000 lines. IBM last September had signaled this was one direction it intended to take within the next 18 months as part of its effort to open up its proprietary architecture (EN, Sept. 16). The software, DFDSM Release 1, will have limited availability in Q4 92, but IBM would not provide a general availability date.

"This is just the beginning of what we're going to do with SMS outside of the boundaries of the glass house," promised Jon Judge, AdStar's assistant general manager for marketing.

In the short term, however, the enhanced subsystem, DFSMS/MVS Version 1 Release 1, is expected to be particularly crucial in winning customer acceptance for IBM's new automated tape storage library, the 3495. As expected (EN, May 11), the library is a linear configuration with a maximum length of 92 feet and capacity of 18,920 half-inch cartridges. Using the 3490 tape subsystem's support for data compression, double-length tape and 36-track density, which gives each cartridge an industry-leading 2.4GB of capacity, the library can store up to 45.5 terabytes of data in its high-end L50 configuration. The L50, which can accommodate up to 64 of IBM's 3490 tape transport subsystems, runs $851,000.

The hardware uses a single, off-the-shelf robot which requires the subsystem to be stopped for any massive exchanges of cartridges through a high-capacity I/O window. IBM officials acknowledged they hope to boost peak performance from a current 200 mount/demount cycles per hour by adding another robot in the future. By contrast, competitor Storage Technology's 6,000-cartridge, silo-shaped unit offers 170 mounts per hour currently and will move by next February to a new generation that doubles that.

Asked why a six-axis robot was required to access what is essentially a two-dimensional array of cartridges, IBM officials cited the unit's high reliability. Privately, however, one official acknowledged a six-axis unit was required in part because the 3490 tape sub-system was not designed with an automated library in mind and presents cartridges to the robot at a range of different angles. IBM officials wouldn't identify the source of the six-axis robot, but it closely resembles the General Motors-Fanuc GMF robot widely used in automotive applications.

Competitors seized on these and other details to maintain that IBM would have a hard time making headway in the market. "It's a piecemeal approach. If I wanted to put out a minimal product that wouldn't affect my DASD sales, this is what I would do," said Joe Beal, who manages the libraries business at StorageTek, the industry leader that is most challenged by IBM's entry.

IBM officials, by contrast, argued that its actual hardware configuration was the least important element of the library, next to SMS and the features, such as 36-track, that are offered by the 3490 tape subsystem. Unlike competitors, "We're not merely automating the mechanical function," Mr. Judge asserted. Rather, he argued, SMS allows users to match specific storage needs to the most cost-effective medium, and manage the whole complex automatically with an increasing array of enhancements in the coming years.

The subsystem was devised in cooperation with Sears, Roebuck & Co., a major IBM mainframe site which will receive an early unit next month. Mr. Judge said IBM was "completely oversubscribed with customers who have asked to be part of our early-support program," but declined to project anticipated demand. General availability is set for Q1 93.

While some observers believe IBM has been disappointed with the pace of migration by customers to 36-track capability, Mr. AbuZayyad said the technology itself hasn't encountered resistance. "If there was any hesitancy, it was more related to would we have the automation to go along with this technology," he said.