Windows Storage Server 2008 includes virtual improvements

Microsoft took the wraps off Windows Storage Server 2008 last week, claiming improvements in its block storage capabilities, single-instance storage and performance.

Windows Storage Server 2008 adds an increase in scalability for file-level single-instance storage (SIS) repositories, and a newly integrated software iSCSI target that can operate alongside network-attached storage (NAS). Microsoft did a deep dive into these and other features during a webinar Thursday, one day after releasing Windows Storage Server 2008 to OEM partners.

Windows Storage Server is sold by Microsoft through storage OEMs such as Compellent, Dell/EqualLogic, and Hewlett-Packard/LeftHand Networks that often use it as a NAS gateway for block storage devices. Those OEMs will have the choice of rolling out their own versions in the coming months, said Jason Buffington, senior technical product manager for Microsoft's storage solutions team.

The first version of SIS from Microsoft was limited to six volumes, but Storage Server 2008 boosts that to 128 formally supported volumes, with 1,024 as a hard limit. Previously, SIS could not be applied to volumes attached to clustered servers, but that restriction has been lifted with the 2008 version. Microsoft's snapshot-based Data Protection Manager (DPM) will now take snapshots of data-reduced volumes without "reinflating" multiple file copies. SIS can also now be remotely administered from a command-line interface, and can be undone once it is applied to a volume.

"The expanded single-instance-storage capability is a key feature of WSS 2008," Enterprise Strategy Group (ESG) analyst Terri McClure wrote in an email to SerarchStorage ANZ.

In a recent ESG survey of 492 storage buyers, reducing operational and capital costs were the two most important considerations for justifying IT spending in the next year, she added. "The expanded SIS support will help drive down both," McClure wrote.

Previously, Microsoft offered the iSCSI software target it acquired with String Bean Software, Inc. as part of a separate product called the Windows Unified Data Storage Server (WUDSS). Going forward, according to Buffington, there will no longer be a separate multiprotocol product. iSCSI virtual hard disks on Storage Server 2008 can now scale up to 16 TB capacity. That target also now supports IPv6, IPSec and CHAP security standards, and multipath I/O (MPIO).

Performance improvements with this release largely come from features already rolled out with Windows Server 2008, such as a 64-bit operating system. Another feature Microsoft calls Server Message Block version 2.0, or SMB2, cuts down on the "chattiness" of the CIFS protocol. Windows Server 2008 also includes a single-namespace distributed file system (DFS), and File Services Resource Manager (FSRM), a Windows-Explorer-like GUI for managing files. FSRM includes management for NFS volumes in the same GUI that has been available to manage CIFS shares.

Forrester Research analyst Andrew Reichman said NFS management improvement will be a key feature for users of the products that include Windows Storage Server as a NAS gateway. "This is widely deployed as a bolt-on to a lot of storage vendors' block solutions," he said. "Historically the NFS aspect of Windows Storage Server has been poor. I think they're trying to overcome that."

Microsoft's storage releases such as the first rollout of Data Protection Manager have worried storage vendors that it was planning to take over the enterprise storage market, but it turns out products such as Data Protection Manager and Windows Storage Server have been nothing to worry about.

"As general purpose storage, it's limited to pretty small environments, still," Reichman said of Windows Storage Server. "I don't think Microsoft has the credibility in the enterprise storage market or scalability in this product to go head to head with enterprise storage options."

Microsoft reps on the webcast said OEMs will be able to tune Windows Storage Server 2008 to boost performance for different hardware. They can use optional commands such as "treat host as stable storage" to cut down on caching, and "continue-interrupt affinity policy" to assign certain processor cores to "listen" to certain NICs for high-priority storage traffic.