General discussion

Locked

Exchange: Slow Performance

By PSX ·
I know a lot of questions have been asked regarding slow Exchange performance but none of them seem to answer my question.

Environment: NT4 SP6, Exchange 5.5 (not a PDC or BDC), 50-user network (around 40 use email).

Problem: My Exchange installation has been running for about 2 years without a hitch. Recently however it started to have problems, namely slow connection. Initial connection to the server (after you click the Outlook icon) is normal. Everything is fine except when the user opens an old email or and old email with attachment. There is a delay of 5-10 seconds for every old email with an attachment. Most old emails without attachment open up quickly except for a few.

I examined the Application and System logs but nothing unusual was found. It looked like a network problem so I teamed up the NICs to double the bandwidth but that didn't seem to help. What is going on here? Can somebody help?

BTW: All users are set to connect to the server via the Exchange connector (LAN connection). Some are laptop users but I don't think that's the problem because we had them since the beginning.

This conversation is currently closed to new comments.

7 total posts (Page 1 of 1)  
| Thread display: Collapse - | Expand +

All Comments

Collapse -

Exchange: Slow Performance

by PSX In reply to Exchange: Slow Performanc ...

Point value changed by question poster.

Collapse -

Exchange: Slow Performance

by curlergirl In reply to Exchange: Slow Performanc ...

I don't think your problem is bandwidth. It might be a few things. First of all, make sure you have installed the latest service pack (SP4, I think) for Exchange 5.5. If your Exchange db has grown considerably, you need to be sure that you have enough free space on the HD where the DB is stored, and that you have enough physical resources (memory particularly) to handle the DB. The STORE.EXE process will grab as much memory as it needs, but as the db grows it will need more, and if you haveother processes running on the same server, it might not be able to get enough memory to run as fast as it should.

Also, have you ever done an offline defrag of your database? You might want to check to see if it is very fragmented - look for Event ID 1221 in your application log for MSExchangePriv and MSExchangePub. These events are generated when the automatic maintenance tasks run and will show you how much free space is left in each db after defragging. If you have more than 10% or soof free space (i.e., 100MG for every 1GB of your db size), then you should probably do an off-line defrag. This is done by running eseutil /d - all Exchange services must be stopped, and you must have at least 150% x the size of your Exchange db offree space on your drive (i.e., if your Exchange db is 1GB, you must have at least 1.5GB of free space to defrag). BE SURE you have a good backup of your Exchange dbs before you do this - I've never had a problem, but it's always good to have insurance anyway!!

Collapse -

Exchange: Slow Performance

by curlergirl In reply to Exchange: Slow Performanc ...

Another thing you might try if you are using Win9x workstations would be to put a HOSTS file on the workstations pointing to the IP address of your Exchange server. This will ensure that the workstations can resolve the Exchange server's host name to IP as quickly as possible. I've seen this problem sometimes on Win9x workstations on a network where you are using WINS for internal resolution and DNS for external (i.e., Internet access). I was never able to find out exactly why, but it seems that this can cause slowness in Outlook/Exchange.

Hope this helps!

Collapse -

by PSX In reply to Exchange: Slow Performanc ...

I tried running the offline defrag utility (eseutil /d). It shrunk the database to 75% of its former size, which is very good, and it sped up the performance a little bit but many old attachments still have the same problems-they take up to 10 seconds to open up while a "please wait while Outlook communicate with your Exchange server" message displays.

The HOSTS file solution does not apply in this case because I've been testing this on Win2K machines.

Any other solution you can think of?

Collapse -

by curlergirl In reply to Exchange: Slow Performanc ...

Are you using any antivirus scanning software at the server level? This would be something like Norton Antivirus for Exchange that scans on the server database level as email comes in. I know specifically for NAV that if you don't have it configured to do background scanning, it will scan every attachment as it is opened. This can definitely cause slowness opening attachments and would be more likely to affect you when opening older attachments that haven't been opened recently. If you are using NAV, there is a setting in the admin console that tells the system to perform background scanning. Make sure this switch is ON - this way the attachments will be scanned in the background while the server is idle, rather than waiting until they are opened to be scanned. Other Exchange-level antivirus products may have the same option, although NAV is the only one I have extensive experience with.

This is the only other thing I can think of that would affect attachments only. Hope this helps!

Collapse -

by PSX In reply to

Poster rated this answer.

This is exactly what is happening. Symantec Antivirus for Exchange was set to scan each attachment as they are opened thereby creating the delay. I changed it to scan attachments in the background and the delay went away.

Thanks for your help. Your answer was dead on.

Collapse -

by PSX In reply to Exchange: Slow Performanc ...

This question was closed by the author

Back to Software Forum
7 total posts (Page 1 of 1)  

Related Discussions

Related Forums