IBM Pushes Shark's Copy Buttons

IBM Corp. (NYSE: IBM) is staying away from the bandwidth catfight between Hitachi Data Systems (HDS) and EMC Corp. (NYSE: EMC) -- instead, it's highlighting new data-replication features for its Enterprise Storage Server (a.k.a. Shark) (see IBM Shark Boosts Replication).

Big Blue this week previewed several enhancements to Shark, scheduled to be generally available June 27, which include new versions of FlashCopy and Peer-to-Peer Remote Copy (PPRC); new "capacity on demand" options; and better performance for read-only data.

"While some of our competitors are pointing to bandwidth and trying to confuse the issue, we're providing additional functionality to our customers," says Jim Tuckwell, marketing manager for IBM's Enterprise Storage Server (ESS).

Of course, IBM may be sidestepping performance because Shark doesn't even come close to matching the claims of either HDS or EMC. The ESS 800 provides 1.28 GByte/s of internal bandwidth, via eight 160-MByte/s Serial Storage Architecture (SSA) loops, according to IBM. By comparison, EMC claims its top-of-the-line Symmetrix DMX2000 delivers 50 times that -- 64 GByte/s -- and HDS says the Lightning 9900V offers 10.6 GByte/s of data bandwidth (see EMC vs HDS: Bandwidth Brawl and Does EMC's DMX Measure Up?).

But Ed Broderick, principal analyst at consulting firm Robert Frances Group, believes IBM's Shark is competitive in terms of overall performance. Besides, he says, that's just one element of a larger set of buying considerations."I think the vendors' claims about bandwidth are arguable... but there's not enough candy in the bandwidth question to convince customers to switch vendors," he says.

Tuckwell, for his part, says theoretical maximum performance claims are meaningless when it comes to real-world customer environments. "It's like arguing whether a Maserati, Lamborghini, or Ferrari can go faster on a public highway," he says. "If you go faster than 70 mph, you go to jail."

With its latest tweaks to the Shark, IBM says it has focused on boosting the system's business-continuity capabilities. For example, version 2 of FlashCopy, the Shark's point-in-time copy utility, is able to perform setup 10 times faster than before. Previously, FlashCopy setup could take up to 8 seconds for very large volumes, during which time the data is unavailable; with version 2, that setup is less than 1 second.

Other features of FlashCopy V2: It can copy to up to 12 targets, compared with only one previously; it's able to span multiple logical storage systems; and it provides dataset-level copy for S/390 and zSeries systems.

PPRC V2, meanwhile, includes an Asynchronous Cascading feature that combines synchronous and asynchronous replication without requiring any additional software. For example, a user can perform a synchronous copy across a metro-area network to a second facility, and then have that immediately cascade to a third site asynchronously. To achieve the same functionality, an EMC customer, by comparison, would need to purchase both Symmetrix Remote Data Facility (SRDF) and TimeFinder.Meanwhile, an ESS microcode upgrade -- version 1.2.2 -- provides a few other features, including better interoperability with Microsoft Corp. (Nasdaq: MSFT) Windows Server 2003 and UnitedLinux operating systems, including SuSE Inc. 8. The upgrade also gives the command-line interface (CLI) for ESS the full functionality of the graphical management tool.

The ESS microcode upgrade fine-tunes the system's caching algorithms, an improvement that IBM claims provides up to 50 percent better performance with AS/400 server environments and up to 25 percent with zSeries mainframes for sequential-read applications, such as data warehousing or video streaming. Sequential-read performance with Intel-based servers isn't affected, IBM says.

In addition, IBM has expanded its standby capacity-on-demand program. Now customers can install up to six 8-drive trays -- for up to 6.9 Tbytes -- for 10 percent of the list price of the storage. When users needs more storage, they pay IBM for the disk and then "unlock" the additional drives. Before, IBM offered a maximum of two drive trays for a 25 percent fee. "Customers wanted more flexibility in the capacity-on-demand options," Tuckwell says.

By the end of the year, IBM plans to deliver PPRC over Fibre Channel; currently, PPRC works only over the Escon protocol. It also plans to enhance the ESS API set to give third-party management tools access to its copy services.

The Shark upgrades come as IBM has unveiled a new mainframe, the zSeries eServer z990 (code-named T-Rex), which the company says is three times faster than the previous model, the z900.Todd Spangler, US Editor, Byte and Switch