The IT group inside Microsoft uses File Server Resource Manager (FSRM) as a centralized tool for managing file servers located in branch offices and data centers around the world. FSRM, which is found in the Windows Server 2003 R2 system, helps Microsoft IT staff to better monitor, control, and manage the quantity and types of data stored on the company’s servers. They write up the results here, including:

Benefit

Source or Derivation

Administration

50 percent less time to manage file servers

Once a hard quota system has been deployed

Hardware

15 percent reduction in hardware costs

Based on ability to more precisely measure current use and gauge future need

Operations

25 to 50 percent reclamation of storage on existing servers, on average

FSRM reports on Least Recently Accessed Files and sending automated e-mail messages to users

Operations

Projected 1.8 terabytes storage reduction

Based on 55,000 Microsoft employees, and some 35,000 partners and vendors using Microsoft IT resources each deleting just 20 megabytes of unused data through FSRM quotas. Actual reduction anticipated to be much greater.

The cfs bloggers pass on some perf data for your estimates:

Quotas: Unlike Win2K quotas, which you could only apply at the volume level and which relied solely on file ownership to determine disk utilization, quotas in R2 SRM can be assigned to individual folders or sets of folders. Internal benchmarks have consistently shown I/O performance cost of less than 10% for tracking quotas on a volume. The cost remains fairly flat with volume size and number of quotas.

Screening: Want to keep user's pesky audio and video files off your server? Based on file extension (such as .MP3 or .WMV or even, dare we say - .PST)you can set policy to either actively prevent writing these files to the server, or you can set the policy as passive and allow users to write, but audit policy violations for follow up or chargeback. The I/O performance impact is negligible for this feature.

Reporting: You can get usage statistics reports by file size, owner, least recently used files, duplicate files and more. SRM can generate reports automatically every night so you can come to morning meetings armed with enough paper printouts to keep even the most detail-oriented manager happy. NOTE however: Running reports can negatively impact server performance. It is recommended that storage reports be scheduled for off-peak hours.

TechNet chat has a good FSRM chat transcript here.