The Mole #12: Technical Answers from Inside Microsoft - PPTP, Pagefile Size, Exchange versions, Default MAPI, BackTalk
July 5, 1999
Editors Note The questions and answers below are from the Inside Microsoft column that appears regularly on the TechNet Web site (https://www.microsoft.com/technet). To find out how to submit questions of your own, see the end of this article or go to https://www.microsoft.com/technet/community/columns/insider/default.mspx.
The TechNet Mole provides expert answers from deep within Microsoft to questions from IT professionals. This installment focuses on these issues:
Network connection speeds on VPNs
Finding the right pagefile size
Exchange version compatibility
Determining your default MAPI client
BackTalk: Mole suffers from paw in mouth disease
On This Page
PPTP Connection Speed on VPN
Choosing the Right Size for Your Pagefile
Invisible Mailboxes: Exchange Version Glitches
Determining Your Default MAPI client
A Bit o' Backtalk
Got Questions? Mail the Mole
PPTP Connection Speed on VPN
Mole,
I recently installed VPN at my corporate office on an NT server 4.0 with option pack 4.0. I have 7 VPN connections set up to communicate through a 128k connection to a router. The same server is my Web Site; little or no traffic there. It also serves as my Exchange server—again very little traffic there. I have six stores dialing up to my server using the VPN and PPTP. They transfer less than 2MB of data to corporate a day.
My question is why is the PPTP connection sometimes connects to the network at 9600 bps when I have a 44,000 ISP connection at the Store. This is using MSN as my ISP. I have found no way of making it connect at a higher rate. Is this to do with the bandwidth of the connection or is my modem not really connecting at 44,000 bps? I also might get a 44,000 bps PPTP connection at the same store on another day. The problem is, when I issue the net use command to map a drive to copy the file, it is either too slow or doesn't make the connection at all.
Kevin Robertson, Dir. of Information Systems, Harpers Restaurants
Hey, Kevin
Okay, the first thing you need to know about the Dial Up Network monitor is that the numbers it shows you are bogus. They have little or nothing to do with the actual speed at which your modem is transferring data. The villain here is data compression, which messes up the throughput calculations. Your best indicator of true transmission speed is probably empirical. If it seems fast enough, it probably is, in spite of what the little numbers say.
If you're still unhappy with the performance of your network connection, though, it's time to review your configuration to see if something needs to be tweaked. Here's your homework, Kevin.
You may already have read the PPTP whitepaper, but if not, check out the MS Windows NT Server 4.0 PPTP Whitepaper.
Virtual Private Networking: An Overview
161516: Troubleshooting Modem Problems Under Windows NT 4.0
161986: Troubleshooting Internet Service Provider Login Problems
162847: Troubleshooting PPTP Connectivity Issues in Windows NT 4.0
The answer to your specific situation is in there somewhere. And by the time you've finished all that reading, you'll definitely be the resident expert on VPNs.
Choosing the Right Size for Your Pagefile
Dear Mole,
We have Some NT Severs with SP 4 running on Compaq Prosignias 300's with 4.3GB hard drives. Software being used is Sybase SQL Anywhere, Cbord FMS and Diskeeper Lite.
1st question: If you make the pagefile on the system too big what problems could occur? We have systems configured with 64 MB of RAM and the Page File is set as the following: initial size 200 MB and maximum size 200 MB.
2nd question. We are having a problem with the pagefile appearing to be corrupt. We determined this by moving the pagefile to a different partition. This is having to be done continuously on some systems, why is this?
Markus Steele (MCP), Impact Innovations Group
Marcus,
First things first. You want to know about the potential downside if your pagefile is set too big.
A pagefile that's set too small can lead to overactive disk swapping, or "disk thrashing." The only real drawback with a relatively large swapfile is that you might not have as much disk space available for other uses as you would if you'd followed the pagefile setup recommendations. The formula suggests you start with "amount of RAM + 12 MB." In your case, that comes to 76 MB.
To figure out if that's realistic, you'll want to monitor the actual usage of the swapfile over several days. To monitor disk activity using Windows NT Performance Monitor, execute the "diskperf" command while logged on as a member of the Administrators group. Then watch the "pagefile usage peak" object over several days of typical server use. It would be smart to set the update interval in Performance Monitor to something like 20 or 30 minutes to reduce the impact on your system. You'll find everything you need to know in this KB article—**102020:**How to Monitor Disk Performance with Performance Monitor.
Monitor for a few days to determine your baseline usage. If the usage is, say, below 76 MB, then you'll probably want to set the swapfile Initial Size at 76 MB and the Maximum size at about 100 MB. If the pagefile usage peak is greater than 76 MB, consider setting the Initial Size to that maximum value + 10% and the Maximum Size to something like 140% the Initial size.
The lesson here is that no two machines are exactly alike. Optimum pagefile size is best determined by actual use, not by formulas related to RAM.
You also want to know about apparent corruption of your pagefile.
The best answer Mole can give you without access to your particular system is to share the questions he'd ask if he had it.
How are you determining that the pagefile is corrupt?
Is the pagefile on a compressed disk? (Okay, this is a long shot, but it never hurts to check.)
What are the differences between the systems that display this corruption and those that don't? Look at hardware, software, disk format, and compression, anything that might be different.
Since the pagefile is recreated after each boot of Windows NT and is not a "permanent" file in the traditional sense, Mole wonders about hardware problems—as in, disk or controller. The utilities you mention are also prime suspects. Compare NT servers that do run Diskeeper vs. any other servers that do not and see if the servers not running Diskeeper display this pagefile corruption problem. There are no reported problems relating to Diskeeper, but a utility that defrags disks deserves close scrutiny. Mole could not find any information on "Cbord FMS". If all other roads wash out, contact the manufacturer and see what they know.
Invisible Mailboxes: Exchange Version Glitches
Mole,
We have 5 sites each with Exchange servers. Four sites are running Exchange 4.0, one is running version 5, service pack 2.
Site 1: 3 Exchange ver. 4 servers, service pack 5
Site 2: 1 Exchange ver 4 server, service pack 3
Site 3: 1 Exchange ver 4 server, no service pack
Site 4: 1 Exchange ver 4 server, no service pack
Site 5: 1 Exchange ver 5 server, service pack 2
When a mailbox is created or deleted on the ver 4 sites, the changes do not show in the GAL of the ver 5 site. This all started when we applied service pack 5 to the three servers at Site 1.
Jon Coad, Support Analyst
Hi Jon,
Reluctant as Mole is to sound like a salesman, your best shot really is to upgrade all your servers to Exchange 5.5 plus the latest service pack. It's not just that 5.5 is generally more stable and reliable, it's that having all your Exchange servers on the same version is a major painkiller for IT headache # 17694—Multiple Version Miseries.
If upgrading your environment to Exchange 5.5 is not possible, then at very least, you should use the latest Exchange version's administration program when you reconfigure any of the servers. There are going to be differences between versions' internal configuration (schema), where an older version may not "know about" a newer version's capabilities or configuration. Making changes like adding or removing mailboxes from your Exchange 5.0 Admin program is the way to go.
Finally, Mole feels duty-bound to include an infomercial. You'll find a TON of information on TechNet or the Microsoft Exchange Server web site (https://www.microsoft.com/exchange/), including a free trial version of Exchange 5.5, a 5.5 Features Guide, Datasheet, and a Deployment & Administration paper. Also, think about going to the 1999 Exchange Conference. It's the first week of October, in Atlanta. This is a popular conference and always sells out.
Determining Your Default MAPI client
Mole,
I reinstalled Videomail after I uninstalled it due to a problem with video...now after reinstall, the Video is running good and I'm not able to use mail button to send the mail via Microsoft Outlook as I did the with first installation. I contacted my vendor (SmithMicro) and they said to contact Microsoft to be sure that Outlook is still configured as the Windows default MAPI client??? Any solution on this one???
Jimbo
Hey Jimbo,
You haven't told Mole whether you're using Microsoft Outlook or Outlook Express, so he answers for both versions and leaves it to you to pick the appropriate remedy. (Remember, girls and boys! The more specifics you give Mole, the better his answers will be.)
Here's how to verify whether Outlook Express is the default MAPI client:
In Outlook Express 4.x, from the Tools menu, choose Options.
Click the General tab, and clear the "Make Outlook Express my default Simple MAPI client" check box.
Click OK, and then click OK again.
Restart the system.
Note that other MAPI-enabled applications such as Microsoft Exchange, Microsoft Outlook, and Windows Messaging will be disabled if you make Outlook Express your Simple MAPI client, but they will work again when you deselect this option.
And here's how to check if Outlook is the default MAPI client:
Start Control Panel, Mail.
Click Show Profiles. You should see the following window.
Look in the box titled "When starting Microsoft Outlook, use this profile." If it doesn't already say "Microsoft Outlook", then make it so.
Restart the system for good measure.
Test this and have your report on my desk by morning. (Only kidding.)
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A Bit o' Backtalk
Mole;
Please do not patronize Australians as you did to Russ Winter. We are technical IT professionals who deserve every bit as much respect as American IT professionals.
Stewart Robertson, I.S. Business Intelligence, Yorkshire Electricity, Limewood Approach, Leeds
Got Questions? Mail the Mole
Communicate with Mole at [closed account]. Send him your toughest questions. And if you think you have a better answer than Mole's, or a different one, send that along, as well. Please include the following:
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Credits
Mole thanks Chuck Anderson, Lon Collins, Michael Conrad and Lester Russell.
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