IBM takes 'virtual' steps with SFS

By Heidi Biggar

IBM last month took what some analysts say are significant steps forward in its virtualization strategy with the 2.1 release of TotalStorage SAN File System (SFS). Notably, the new release includes support for non-IBM disk storage, additional operating systems, and virtually unlimited capacity.

To the surprise of many, after a prolonged period of miscues with its initial release of the software, IBM has stayed pretty much on course with the 2.1 release. IBM first introduced the file system in November 2003.

The initial SFS release garnered mixed reviews from analysts. On one hand, analysts were impressed with the sheer magnitude of the endeavor, but they also questioned IBM's ability to deliver key pieces of the technology—such as true heterogeneous disk and server support—over time (see "IBM delivers SAN file system, falls short," InfoStor, November 2003, p.1).

Designed to facilitate high-performance heterogeneous file sharing and access in a SAN environment, the initial release of the file system only supported IBM disk arrays, Windows, and AIX. For heterogeneous block-level disk support, users could run IBM's TotalStorage SAN Volume Controller (SVC).

"You could use SVC to virtualize disks at the subsystem level, but you couldn't attach them natively," says Jeff Barnett, manager of strategy for IBM storage software. "Now customers can use any SAN-attached storage with SAN File System 2.1."

IBM hopes that this additional support will open new doors for the company in its ongoing battle for storage system and management software market share, particularly against archrival EMC.

According to International Data Corp. (IDC), EMC led the external disk storage market in the first quarter of this year with a 20.2% revenue market share, compared to Hewlett-Packard (18%), IBM (12%), and Hitachi Data Systems (9.7%). IDC also lists EMC as the revenue leader in the storage management software market, with a 30.7% market share in the fourth quarter of 2003, compared to Veritas (21.3%), Computer Associates (9.3%), IBM (8.6%), and Hewlett-Packard (7.9%).

TotalStorage SAN File System 2.1 supports all SAN-attached storage (as long as it supports SCSI), which includes arrays from EMC, Hewlett-Packard, Hitachi, and others. The file system also now supports Red Hat Linux Enterprise Server 3.0 and Sun Solaris 9.

"This is a significant but incremental announcement," says Charles King, research director at the Sageza consulting firm. "They're not done yet, but they've taken a pretty big step down the road to the long-term goal of offering users fully virtualized storage management across multiple platforms."

Like other large vendors, such as EMC, HP, Hitachi, Sun, and Veritas, IBM is working toward the long-term goal of utility computing (i.e., getting to the point where it won't matter what type of disk arrays or server platforms you're running), explains King.

"Access to data will be ubiquitous and the difference between [storage devices] will amount to the difference today between Westinghouse and GE light bulbs," says King.

But analysts also note that this scenario is many years away. Until then, vendors continue to work on the underlying infrastructures for utility computing, and virtualization—in its many formats—has emerged as one of the key enablers. The SMI-S management standard is also expected to play a key role in this objective.

"The dream of IBM's virtualization is to deliver full-fledged management of heterogeneous devices attached to a single infrastructure," says King. "Another way to do this [other than via virtualization] is based on SMI-S, [although] SMI-S will likely matter more with future hardware generations."

The IBM virtualization family consists of TotalStorage SFS, SVC, SAN Integration Server (which integrates virtualization, storage controllers, and Fibre Channel switches), and SAN Volume Controller Storage Software for Cisco MDS 9000 switches.

SFS and SVC can be used separately or in combination (see table). SFS and SVC are designed to aggregate file-level and block-level data, respectively. "By combining block virtualization and a common file system, users should be able to simplify their operations and more efficiently manage their storage resources," explains Barnett.

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Though the two products can be scaled to meet a range of industry and market segments, IBM says SVC is best-suited for midrange to high-end environments while SFS is geared primarily toward the high end of the market. Barnett says SVC may be of particular interest to companies that already have midrange to high-end SANs in place and are looking to better manage storage volumes in these environments.

In these environments, SVC can provide a single view of storage volumes, which can help users migrate volumes, add capacity, and do performance/software upgrades. This can lead to increased administrator productivity and lower TCO, according to IBM.

The SVC can be implemented as an in-band appliance or embedded in a blade on, for example, the Caching Services Modules of a Cisco MDS 9000 switch.

SFS, meanwhile, provides a central point of control for the management of files and databases as they relate to specific business needs. The file system allows users to create a storage pool, which can be segmented according to business/application requirements and pre-

defined policies. Participating servers have access to this global namespace, which means users can share files easily and efficiently, according to IBM.

"The idea is to give users a choice of technology," says Barnett. "You could have one IBM Enterprise Storage Server that you want to continually leverage in the SAN File System, or you may have a lot of storage arrays that you want to manage with SVC [or you can use both]."

Fotango, a subsidiary of Canon Europe, is using both the SAN File System (the first version) and SAN Volume Controller to manage the storage resources for its online photo-sharing service. Fotango's SAN consists of three IBM eServer pSeries servers running AIX, as well as FAStT200 and FAStT700 storage systems.

Virtualization products are also available from Hewlett-Packard (Continuous Access Storage Appliance, or CASA) and Veritas (Veritas Volume Manager). EMC this quarter is also expected to begin beta testing of a standards-based storage router that will create a virtualization layer, which will tie applications and the storage infrastructure together, allowing for dynamic movement of both applications and information (see "EMC focuses on ILM," InfoStor, June 2004, p. 1).

In response to the ongoing virtualization battle between EMC and IBM, Sageza's King says: "IBM is a bit ahead."

This article was originally published on July 01, 2004