New version of Windows NAS makes the grade

Found to be fast, difficult to misconfigure, highly efficient, useful.

In our Clear Choice Test of Microsoft's latest version of its file-pinching network-attached storage software - dubbed Windows Storage Server R2 - we found it to be fast, difficult to misconfigure, highly efficient and a useful storage operating system for both local drop-and-add NAS boxes and branch office storage devices.

In our Clear Choice Test of Microsoft's latest version of its file-pinching network-attached storage software - dubbed Windows Storage Server R2 - we found it to be fast, difficult to misconfigure, highly efficient and a useful storage operating system for both local drop-and-add NAS boxes and branch-office storage devices.

How we did it

Archive of Network World tests

Subscribe to the Network Product Test Results newsletter

Overall, we found this version of Storage Server contains several features especially suited to branch operations, including sparse file management, reduction of redundant files and an extremely proficient backup mechanism.

Windows 2003 Storage Server R2, released last month, cannot be purchased directly by consumers, but is sold as part of an OEM NAS appliance. We tested OEM samples of this code from HP and Dell. The software is sold to OEMs in four iterations: Express, Workgroup, Standard and Enterprise.

The Dell product tested was a large desktop server unit; the HP NAS box came in a 1U rack server. The Dell unit ran Windows Storage Server R2 Standard Edition, which supports all features; the HP box supported Wordgroup Edition of the Microsoft software. The Workgroup edition can report itself as an Standard Edition, so check which version you're getting, or you're in for surprises.



HP (starts at $2,500), Dell (starts at $2,500).
Pros:Very efficient NAS, easy drop-and-add features, very good feature set to match Windows networks.
Cons:Needs administrative tuning features; not really non-Windows client-friendly.
The breakdown
Installation/integration 25%4*Scoring Key: 5: Exceptional4: Very good3: Average2: Below average1: Subpar or not available
Management/administration 25%4
Performance 25%4.5
Security 25%4

This software uses two main methods to achieve far higher efficiency in storing and transmitting file information: Single Instance Storage (SIS), which reduces identical instances of files to a single file with appropriate stubs or place holders for other copies; and its function that records delta-only file changes. We tested these functions discretely and in combination with another feature of the software - enhanced Distributed File System (DFS) - for failover and availability.

The SIS service, which is not supported in either the Express or Workgroup versions, reduces file duplication across multiple machines. It runs in the NAS server and monitors files being written to the server. Once the first instance of a file is stored on a Windows-based NAS appliance, subsequent identical files aren't stored there; file stubs pointing to the initial copy of the file are stored in their place. This yields a great savings in server space.

For organizations that use the Windows-based NAS box to store many unique personal documents, the savings will be small. However, organizations that launch a static fleet of applications from network resources will see a comparatively dramatic reduction in the overall displacement of these kinds of files, in our testing more than a 90% space savings.

Microsoft's existing DFS creates a replication scheme where a namespace (also known as alias name) represents shared folders (or shares) that are replicas of the files represented by the shares. If a file changes on one host, it is replicated according to administrator-defined rules to other hosts sharing the same namespace, thus synchronizing them. If a large file is modified, that file typically is replicated in its entirety to the synchronized host.

Windows Storage Server R2 has new DFS functionality that makes this process easier to manage in branch-office deployments, because it can replicate and synchronize files between the storage server and another Windows-based NAS box or Windows 2003 server anywhere on the network. Rather than the entire file, however, only the delta (with a few bytes for overhead) of a file change is sent across the wire. Compression then reduces the communication time between the changed host and its replica.

We unplugged the DFS running on the local Windows Storage Server R2 appliance to see how long it would take the namespace files to be delivered from its replica and found some initial weakness. The failover from the Windows NAS box to the primary test server took as long as 29 seconds. This seemingly intolerable time lag is a function of the timeouts given to TCP/IP when used with the small-to-midsize business protocols. An obscure registry change (we needed to contact Microsoft for this) shrank this default time to a more tolerable range of 4 to 9 seconds. Tweaking this setting for others will depend on overall network WAN response times. Macs, Linux and other non-Windows clients cannot take advantage of this DFS failover feature yet.

Windows Storage Server R2 contains Version 3 (the latest) of the Microsoft Management Console, which has a snap-in called File Screening; this allows administrators to prevent files of a certain name to be put onto the Windows-based storage server, thereby preventing undesirable applications (think Limewire, MusicMatch files, with extensions used by viruses and Trojans) from infecting the server. It's not a perfect system, because astute users can rename files, but it's one more security hurdle mal-intentioned individuals must overcome, and helps enforce preventive organizational security policy.

Overall, Windows Storage Server R2 adds quite a bit of value for Windows networks compared with more generic NAS devices. It has a few rough edges - in terms of failover response times and configuration issues - but overall, the added value of failover, reduced copying times, and configuration options makes it viable alternative to other NAS appliances.

Henderson is principal researcher and managing director of ExtremeLabs. He can be reached at Szenes is a researcher at ExtremeLabs.

NW Lab Alliance

Henderson is also a member of the Network World Lab Alliance, a cooperative of the premier reviewers in the network industry, each bringing to bear years of practical experience on every review. For more Lab Alliance information, including what it takes to become a member, go to

Copyright © 2006 IDG Communications, Inc.

The 10 most powerful companies in enterprise networking 2022