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Our system admin has been struggling with the issue of our network getting completely locked up when users open PST files from network drives. Apparently Microsoft is aware of this problem but there is no fix for it.

The entire local network is unable to use Outlook while this file is being opened (which may take hours). Is there a way to determine which user is opening the file instead of forcing everyone in the office to close outlook (like a traffic monitor or something)?

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To be honest after asking the question here, I was concerned that maybe it belonged on Superuser (it still seems like a gray area). By the time I had posted it on Superuser there were replies to this thread. – Daniel Feb 23 '10 at 18:12
I would say it belongs here. Not an individual user issue, it is an issue as system admin would probably have to resolve. – Kyle Brandt Feb 23 '10 at 18:15
Right on. Thanks for the clarification. – Daniel Feb 23 '10 at 18:26
Any reference for Apparently Microsoft is aware of this problem? – Arjan Feb 23 '10 at 18:34
@Arjan - the duplicate thread has links to the KB article I reference in my answer below. – mfinni Feb 23 '10 at 18:35
up vote 9 down vote accepted

Microsoft says pst files should not be stored on network drives, so the long term fix is move them off the network drives.

In the sort term, you can configure a mirror port on your switch, and then run wireshark on a computer attached to that port for a packet analysis. The switch might also be able to show bandwidth usage per port on a web interface depending on the model.

Another option would be to use a program that shows open files on server hosting the network drive such as filemon.

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So in the long term you move them off the file server to the desktop, and then enter a world of pain trying to back them up. The only thing that really works is to get people not to keep email forever, or spend lots of $$ on fast storage for the Exchange server. – Kyle Brandt Feb 23 '10 at 18:07
+1. Thanks for mentioning that it's an unsupported scenario. I hate when I hear people say "Microsoft is aware of the problem, but there's no fix.". There is no problem, it's unsupported, so don't look for a fix from MS for it. The fix is don't do it, but if you do, you're on your own. – joeqwerty Feb 23 '10 at 18:28
The best long-term fix I've found for mailbox size issues is conditioning your users to detach/strip off attachments to their network shares. This doesn't even need to be a painful process. In both Lotus Notes and Outlook it's fairly easy to sort all emails by total size, then step though the largest emails and save the attachments off to the network. Once they know to do this and you've sat with them for a few mins to demonstrate, they know how to get around the 'quota exceeded' messages. – Chris Thorpe Feb 23 '10 at 19:51
@Chris Thorpe: Apparently the last time this issue occurred, it was from a user attempting to open a 3 MB .pst file. It's not a size issue. – Daniel Feb 24 '10 at 13:50
A lot of my small biz users run their PST files from a network share, either on Windows 2003 server or Samba service. Some of them have 4 or 5 PST files, each over 1GB in size with thousands of messages. YMMV :-) – DutchUncle Jan 14 '11 at 22:07

It's an unsupported scenario because of the way PST files work:

Have you looked in Computer Management | Shared Folders yet? It might help identifying the culprit.

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Shared Folders is what we use to solve these kinds of problems. It lists open files and who holds them open. Very handy. – sysadmin1138 Feb 23 '10 at 18:14
+1. Thanks for mentioning that it's an unsupported scenario. I hate when I hear people say "Microsoft is aware of the problem, but there's no fix.". There is no problem, it's unsupported, so don't look for a fix from MS for it. The fix is don't do it, but if you do, you're on your own. – joeqwerty Feb 23 '10 at 18:27
I was going to recommend this way to see who has it open. – steve.lippert Feb 24 '10 at 20:48

You can use Computer Management to see who has the file open. On the server with the PST files, right click My Computer, Click Manage. Under Shared Files select Open Files.

Quick and easy

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It's not merely that MS is aware of the problem, they have KB articles that explain why you're not supposed to do this. Solving the problem can involve some or any of these approaches:

  1. Giving the users large enough Exchange quotas, which may also involve training them not to use email to store large PPT and other media files. If there's room on the fileserver for huge PSTs, there's room on the fileserver for the actual files that they're working with.
  2. Getting a third-party archiving tool Symantec Vault.
  3. (out-of-the-box thinking) An IMAP server would do a good job of holding an archive mailbox for each user , and there are many free ones.
  4. Training the users to not open their PST files on the network. Concerns about loss of valuable information in the event of a desktop/laptop crash should be weighed against the cost of local PC backup software, or just giving the users enough Exchange storage anyway.
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To answer the question, go into computer management, click on Shared Folders, then Open Files.

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You could configure auditing on the files, then the server will log who opened it and when. Unlike going to look for open files in the server management tools, you don't have to be there when the opens happen to see them, you can just check the log afterwards.

But yes, the way I got around this before was to add storage to the Exchange server, then upload the PST files to that.

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