Why you should not store PSTs on your file server
Do you store PSTs on your file server? This is a fairly common issue that most people either aren’t aware of or don’t care about for some reason. If you ask me it’s A Bad Thing that should be avoided at all costs. Microsoft has a KB article on this and I’ve copied and pasted a few choice sections out of it below…
The .pst files are not meant to be a long-term, continuous-use method of storing messages in an enterprise environment.
Other Behaviors of .pst Files over WAN/LAN Links
- All operations take longer.
- Write operations can take approximately four times longer than read operations.
- Outlook has slower performance than the Exchange Client.
When you store .pst files, shares may stop responding. This behavior may cause several client-side problems, such as causing Outlook to stop responding or freezing desktops on client computers. Queuing in the Server service work queues is what causes this temporary condition. The Server service uses work items, such as a request to extend a .pst file, to handle I/O requests that come in over the network. These work items are queued in the Server service work queues. From there, they are handled by the Server service worker threads. The work items are allocated from a kernel resource that is called the nonpaged pool (NPP). The Server service sends these I/O requests to the disk subsystem. If, for reasons that are mentioned above, the disk subsystem does not respond in time, the incoming I/O requests are queued by using work items in the server work queues. Because these work items are allocated from the NPP, this resource eventually runs out. Running out of NPP causes systems to eventually stop responding and to log event ID 2019.
Consider one more scenario that is not specifically called out in the KB: real world file server performance. If you have 400 users with 1GB PST files located on a single file server what happens when they all come in at 8AM and load up Outlook? Outlook is going to try to load the entire PST at once and your file server is going to be asked to deliver 400GB of data to 400 users simultaneously. Yet again, A Bad Thing. These are obviously make believe numbers but hopefully you get the idea.
Microsoft makes a few recommendations in the KB, all of which are feasible, but I would add a big one that is becoming more popular daily – Archiving. I’ll write another post that covers some archiving options in the coming weeks but until then know that it allows you to move your user’s older and less frequently accessed e-mail to slower, cheaper storage with minimal impact to the user experience. It also allows you to provide a “bottomless mailbox” as far as your users are concerned as they will never hit their quotas if your policies are designed properly.
[ LINK ] to Q297019 – Personal folder files are unsupported over a LAN or over a WAN link
Categories: Exchange Server
Tags: archiving, exchange, outlook
Comments: No Comments.