Work around DFS limits

Microsoft's distributed file system (DFS) provides a way for users and administrators to have a single, unified view of files spread over many servers in the organization.

DFS allows for easier file management and lets users find things more readily. However, there are some limits to DFS' capacity that can hamper its usefulness.

Although the problems involve running out of capacity, this isn't a matter of physical storage, and adding storage devices usually won't help.

Instead, the problem revolves around built-in limits with DFS and Windows itself. One of the frequent troublemakers, for example, is the 260-character limit in pathnames imposed by Windows APIs. A poorly planned DFS implementation can easily exceed that limit, resulting in an error message rather than a file retrieval.

To mitigate problems, Microsoft recommends several techniques when designing a DFS file system.

• Limit comments. You can comment the root target or link in a DFS system, which is handy for keeping track of the complex structure of a DFS. However, those comments count against length limits, so keep them as short as possible.

• Cascade namespaces. DFS namespaces are limited to 5,000 links. If you need a larger structure than that, you can create multiple namespaces within the recommended sizes and link them together. The links pointing to other links are called interlinks.

• Enable root scalability mode. Root scalability mode lets you use more than 16 root targets. This can greatly expand the size of the DFS and ease management by helping to organize the system.

Microsoft discusses the ...

Digg This!     StumbleUpon     Del.icio.us

RELATED CONTENT Windows Hardware Strategies Availability in the virtualized Windows server Hardware considerations for Windows server virtualization Scaling Windows server resources for virtualization Troubleshooting your toughest Windows server crashes High-tech solutions for monitoring computer heat Server virtualization at the hardware level with Hyper-V Virtualization and 64-bit: A match made in Windows heaven How to use the g4u network-based hard disk cloning utility Multi-core processors on the desktop offer major boost When and how to migrate to a 64-bit platform Windows Server Monitoring and Management How Windows Server 2008 R2 stands up to security checks BitLocker in R2 provides data protection for semi-protected servers Perfmon made easy with PAL utility Converting Citrix XenServer source machines to Hyper-V format Balancing Windows security with reasonable password policies Windows AppLocker in R2: Turning conventional security wisdom on its head Top 10 things you don't know about Windows Server 2008 R2 BranchCache makes branch offices feel like home When to use VM backups versus snapshots in Hyper-V Installing Server Core for Windows 2008 the easy way

RELATED RESOURCES 2020software.com, trial software downloads for accounting software, ERP software, CRM software and business software systems Search Bitpipe.com for the latest white papers and business webcasts Whatis.com, the online computer dictionary

limits of DFS and workarounds in a FAQ at: http://www.microsoft.com/windowsserver2003/techinfo/overview/dfsfaq.mspx

(To learn more about Distributed File System, read our two-part tip, Four easy steps to creating a Win Server 2003 DFS and DFS benefits go beyond the user.)

About the author: Rick Cook has been writing about mass storage since the days when the term meant an 80 K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last 20 years he has been a freelance writer specializing in storage and other computer issues.

• Tip: Tool helps cure consolidation headaches
  
• Topic: Research Storage Management in this topic section
  
• RSS: Sign up for our RSS feed to receive expert advice everyday