IBM takes aim at EMC/HDS/HP/STK
Last week, IBM began shipments of the Enterprise Storage Server (ESS) disk array, marking a return to its "not invented here" stance and an aggressive strike at its primary competitors, including arch rival EMC, Hitachi Data Systems, Hewlett-Packard, and StorageTek. Analysts say that the high-end disk array, formerly code-named Shark, is competitive in areas such as performance and capacity (up to 11.2TB), but that IBM is just playing catch up in other areas, such as multiplatform support.
In a first for IBM, the ESS provides native support for heterogeneous platforms, including System/390 mainframes, Windows NT, Unix, and AS/400. In this respect, IBM is playing catch up with EMC and HDS, which have supported S/390, NT, and Unix for some time. IBM`s support for AS/400 in the same box is not seen as a key advantage because AS/400 storage is predominantly internal, and most AS/400 shops tend to keep their storage separate from other platforms.
On the performance front, however, IBM appears to have a winner. The company quotes specs such as 33,000 I/Os per second in Unix environments; 185MBps sustained sequential throughput in S/390 environments; an 800MBps internal bus bandwidth; and160MBps Serial Storage Architecture (SSA) disk drives. And IBM guarantees performance and availability claims with warranties.
Analysts say the performance specs, if proven in real-life applications, are very competitive with other arrays. The caveat is that the numbers are based on internal benchmarks, and it`s too early for performance results from early users.
IBM is also getting uncharacteristically aggressive on pricing, which may put pressure on competitors such as EMC. The ESS costs 44 cents to 58 cents per MB, and those prices are based on usable (as opposed to raw) capacity and list (as opposed to street) prices.
One question remains, How will IBM position the ESS relative to its Ramac Virtual Array (RVA), which IBM OEMs from StorageTek? (STK`s version is called the Shared Virtual Array.) STK, which is the only vendor that has implemented virtual disk technology, contends that IBM is abandoning the RVA in favor of the ESS. However, at the same time that IBM announced the ESS, it announced an enhanced RVA (again, based on STK`s SVA), that doubles capacity to 1.6TB and boasts a 25% performance improvement.
"We think their focus will shift away from RVA to ESS," says Chauncey Schwartz, director of strategic planning for Storage Tek`s enterprise disk business group. "It seems like they`re going back to a speeds-and-feeds selling style instead of a business benefits selling style." (For more on StorageTek`s reaction, see sidebar "STK`s Shark repellant.")
The addition of the ESS to the high-end array market will provide more choices for users, but may also create confusion. "IBM will eventually supplant RVA," says Mike Casey, research director at the Gartner Group consulting firm, in Stamford, CT, "The question is what the transition plan will look like."
"This is going to be a real confusing time for customers," says David Hill, senior analyst at the Aberdeen Group, a consulting firm in Boston.
According to Mike Harrison, IBM`s director of marketing strategy, IBM will have its own virtual architecture--to be implemented on the ESS--"in the second half of next year." It`s interesting to note that IBM`s OEM agreement with StorageTek, which began in 1996, expires in December of next year.
Harrison characterizes IBM`s relationship with StorageTek as one of "coopetition." "We cooperate with them on RVA, and we compete with them with ESS," says Harrison.
Under the hood
Regardless of how IBM positions its high-end arrays or how the marketing battle turns out, ESS warrants a close look. The performance of the array comes in part from the use of 160MBps SSA drives in a loop configuration. "We believe SSA is a superior drive connect technology, certainly compared to SCSI, but also compared to Fibre Channel because you don`t have the arbitration issues with SSA that you have with Fibre Channel," contends Harrison.
However, the ESS does support Fibre Channel as an external interconnect, in addition to ESCON, FICON, and Ultra SCSI (although native support for Fibre Channel is not due until the first quarter). The interfaces can be intermixed across as many as 32 host ports.
The other key performance boost comes via the exclusive Parallel Access Volumes technology, which is implemented in the array and in System/390 Workload Manager software. PAV, which applies only to S/390 environments, significantly reduces contention by solving volume queuing problems in the S/390 architecture. PAV allows multiple requests for the same volume of data, or a single request to multiple volumes of data. Result: reduced response times. However, because PAV is implemented mostly in the operating system, competitors could eventually take advantage of the performance advantages via microcode changes.
The ESS will also get a number of software enhancements, including remote copy and FlashCopy point-in-time copy, in the first quarter of next year. However, IBM still trails EMC, HDS, and HP in software support.
"IBM was lagging in software because they didn`t have a multiplatform-attachable box until now, and EMC and HDS have had that for a long time," says John McArthur, program director at International Data Corp., a market research firm in Framingham, MA.
ESS hardware summary
Dual four-way SMP PowerPC RISC processors
420GB to 11.2TB total capacity
6GB cache (16GB next year) with 384MB nonvolatile write cache
9/18/36GB SSA disk drives
4 to 32 server connections using SCSI, ESCON, FICON, FC-AL, and/or Fibre Channel
RAID 5 or non-RAID (JBOD). RAID 1 due second half of next year.
Redundant power, cooling, adapters, buses, processor complexes
List price: 44 cents to 58 cents per MB list