Windows 7: Accessing network drive via DFS namespace hangs

Has anyone experienced this?

I have a Windows Server 2008 file server with DFS Namespace role. The server hosts file services and uses DFS-R to replicate content to another member server. One of the folders has a Users directory where PST files are located. When these files are open, DFS-R will not replicate them but queue them in a backlog. Once the backlog grows significantly, the client machines tend to lock up when trying to access the shared drives. The drives are mapped using the DFS namespace, but even navigating using UNC path will still lock up. This is seen with Windows 7 clients and XP clients seems to be fine. If I exclude PSTs from DFS-R the issue does not occur.

I should mention that there is a DPM 2010 server in the environment that backs up the file/print server. The sync is set to every 15 minutes. Recovery points are during the day and XP and Windows 7 clients can lock up if a recovery point is running at the same time as a DFS backlog. If there is no backlog, all seems to run fine.

Is there some option in Windows 7 that is attempting to index network drives? I've checked the settings in Indexing Options and don't see anything that stands out. Like I said, I currently have PSTs excluded so the issue does not happen right now, but once I enable them and a backlog starts to build, the issue happens again.

Any thoughts would be appreciated.

Thanks.

Well, other than the usual disclaimer about putting a database file on a network share like a PST or OST file, I can't say I've ever seen it before. You'd probably want to get a network trace via netsh or netmon or wireshark of the PC attempting to hit the file, and you might even want to get a trace from the server simultaneously as well. There's nothing inherent I can think of that would cause it, other than Windows 7 would be using SMBv2 to the 2008 box(es), whereas XP would be using SMBv1 - that can have an impact depending on the command responses they are seeing (and whether or not offline files caching is enabled for the location).

Again, PSTs and OSTs on the network are a bad thing, and doing so will only end in tears (if not now, eventually).