The Mole #9: Technical Answers from Inside Microsoft - Memory Leak, Terminal Server, RAW Files, NT as Bridge

May 17, 1999

Editors Note The questions and answers below are from the Inside Microsoft column that appears regularly on the TechNet Web site ( To find out how to submit questions of your own, see the end of this article or go to

The TechNet Mole provides expert answers from deep within Microsoft to questions from IT professionals. This installment focuses on these issues:

  • NT server "memory bleed"

  • Bugs, bugs, bugs…and NT Terminal Server

  • What is a RAW file, anyway?

  • Backtalk:

    NT as Bridge, continued

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Is there such a thing as NT server "memory bleed"?
Got Questions? Mail the Mole

Is there such a thing as NT server "memory bleed"?

Dear Mole:

I am running NT Server V4.0/SP3 as my OS for my web server. After 48-72 hours of very heavy traffic the http.exe showing on the performance monitor is using 98% or so of CPU utilization. It seems the only way to calm the CPU down is to reboot.

System hardware is this: Tyan S1590S Trinity AT motherboard, 368Mb DRAM of fast PC100 memory which utilizes the front side bus, Pent 233 MMX CPU, an ICP-Vortex RAID controller card running 4 IBM WU SCCI 7200 rpm hard drives. One dedicated IBM WU hard drive handles the NT Server OS that has its own Adaptec 2940 UW2 controller card. When fresh the CPU utilization is usually under 10%-15% with the RAID controller handling the hard drives. The site handles about 20k visitors a day spread evenly throughout a 24 hour period.

With the CPU maxed out my credit card processor can't write to a members only database file on the "c:" drive. I am wondering should I be running a mirror for the c: drive or should I do something like run another hard drive dedicated to the TCP/IP stacks? My Linux friends say that it is "NT memory bleed" and that I should migrate to Linux. I absolutely don't want to switch to Linux but I need some kind of solution to this problem.

I am more inclined to think that I may have something mis-configured . . . any advice?


Dear Rainmann,

First, thorough as your description is, you don't mention whose Web Server application you're using. If you know the origin of the file "http.exe," then you can contact the vendor and inquire if they've had reports of memory leak problems. Mole is 99% sure this is a Netscape file, but you'd best do some digging yourself to double check. In Explorer, right click on the file, select Properties, click on the Version tab, and you'll see what company holds the copyright. Now, hold their feet to the fire, okay?

Seriously, whether you're working with the ISV or with Microsoft, having the right info on hand saves time and frustration. When you're troubleshooting a performance issue that appears to involve a memory leak, you'll want to make sure Performance Monitor is, at the very least, logging the following items:

  • Memory

  • Paging File

  • Process

  • Processor

  • Server

  • System

  • Object

  • Threads

A good Knowledge Base article to consult is 175658: Gathering Information for Troubleshooting Performance Issues.

Now, about mirroring the C: drive. It is a good idea, especially with mission-critical servers. By placing only the boot/system partition on a single drive and then mirroring (also known as RAID level 1) to another drive, you will protect the system drive in case of hardware failure. If a hardware failure occurs on the system drive, the server can continue running on the mirrored drive while you repair or replace the failed disk. And oh boy, will you look good.

Here's some reading to help you get set up:

Bugs, bugs, bugs…and NT Terminal Server


I have recently become involved in an NT Terminal Server installation including Hardware RAID arrays. A couple of questions, from my NT Server experience I need scsi hotfix to see the RAID device controllers even when no LUN is defined, although the NT Server scsi hotfix is newer than my NT Terminal Server version, caution is my first thought and I would like clarification if NT Server scsi hotfix is applicable to apply to NT Terminal Server. Also, I hear rumors of NT Terminal Server Service Pack becoming available but cannot find any information regarding this, clarification again of if this Service Pack is a reality and if so, does it contain a Terminal Server release of the scsi hotfix?

Russ Winter, StorageTek Australia


Mole believes that your problem is indeed fixed in the latest Service Pack for Windows NT 4, Terminal Server Edition. And Service Pack 4 (SP4) for Terminal Server is now available. It offers many improvements to Terminal Server, including enhancements to application development, security and application services, as well as updates for all currently known Year 2000 issues for Terminal Server.

You'll be happy to know that SP4 Terminal Server Edition also provides all the bug fixes from Windows NT 4.0 SP4.

You can copy it from the Service Packs CD on TechNet.

Mole recommends that when you dig up a bug in a Microsoft product, you address it with a Service Pack, rather than a bunch of individual hotfixes. Okay, sometimes you need the fix and the SP isn't ready. In that case, test test test the hotfix in a secured environment that duplicates your production environment as closely as possible. If and only when it passes testing should you put the hotfix into production. It's a wise man who covers his outback, eh?

And here's your reading assignment for the week:

  • 222970: List of bugs fixed in Microsoft Windows NT Server version 4.0 SP4, Terminal Server Edition

  • 150734: List of Bugs Fixed in Windows NT 4.0 and Terminal Server Edition Service Pack 4 (Part 1)

  • 194834: List of Bugs Fixed in Windows NT 4.0 and Terminal Server Edition Service Pack 4 (Part 2)

  • 224793: List of Bugs Fixed in Windows NT 4.0 and Terminal Server Edition Service Pack 4 (Part 3)

What is a RAW file, anyway?


When a friend was trying to update a processor (from a Pentium 166 Mhz to a K6 II 350), something happened with one of the disks in Windows NT. The system refuses to identify it or convert it and says that Windows can't convert from the RAW file system. Nobody seems to know what the hell is RAW file system. Microsoft's help desk here in Argentina says almost nothing and navigating through the web I've found that NT supplied an FSD that is the "last resort" for all NT I/O request requiring file system support. Anyway, besides wanting to know what is RAW file system? I would like to know whether there is a way to convert that disk into NTFS or something like that.

Thanks in advance and please do forgive me for the misspellings.


Hola, Gastón:

Your first and most pressing question—what the hell is a RAW file system?—is easy enough to answer. It's simply a disk partition that has not been formatted with an NT file system, neither FAT nor NTFS.

As to the remainder of your problem, Mole feels that too much of the recipe is missing to cook up an entirely satisfactory answer. For instance, was the motherboard changed when going from the Pentium to the K6 processor? If so, there could very well be a problem with what Windows NT thinks is the disk controller and what is actually in the machine. This would cause problems in accessing the disk.

What's the fastest way to solve the problem? You may want to consider a complete re-install of the operating system, followed by a restore of data from the backup you performed prior to making the major hardware change. During the process of installing Windows NT, you will have the opportunity to format the drives to either FAT or NTFS.

One smart option for partitioning your hard disk is to create a smaller primary partition—say 2GB—using FAT, and to designate the rest of the hard drive NTFS. As you probably know, system boot files always reside on the primary partition. This way your boot up is fast, while the bulk of your files can enjoy the additional stability and security of NTFS. Note that with Windows NT 4.0, your hard drive may have only one or as many as four partitions. Going back to square one will let you customize your NT 4.0 installation for maximum performance.

BTW, your spelling is just fine, Gastón. It's your punctuation that looks a little weird…. Now, how about those fabled Argentine steaks?

Whom Do You Trust? NT Domain Capacity

Dear Mole,

Are there any limitations on the number of trust relationships that can be implemented throughout an NT domain?

We have been having discussions within our organization about changing our domain structure. There are currently two options that are being discussed; single master domain and the single domain. The one common objective is to have a single domain logon throughout the UK, enabling a common desktop (roaming profiles) at each site visited.

The company requires approximately five sites (spread throughout the UK) to be linked. The number of users is approximately 4000 expecting no more than 5000. If possible each of these five sites would like to manage their own resources rather than central administration from one location. However we have been informed from a number of sources that when more than four trusts exist these tend to become 'unreliable' and this will obviously not be acceptable.

Any information regarding these comments would be gratefully received.

Ian Leplar, Easams Ltd

Dear Ian,

First, congratulate yourself for being the sort of chap who thinks before he implements. Researching and planning your domain design will pay big rewards later on with a more reliable, robust network.

Given the number of users that will be in the Windows NT domain and the number of sites you propose, the number of trusts that you will need to establish and maintain is not a problem. Windows NT 4.0 has no limitations on the number of incoming trusts (trusted domains) it permits.

You say that your two main priorities are 1) a single logon for all users in the U.K., and 2) that the five sites should administer their own resources. The best plan would be to implement a single Master domain with five Resource domains. In this design, the user and machine accounts would reside in the Accounts domain and each of the five resource domains would establish a one-way trust to the Accounts domain. The advantages are that there would be only five trust relationships to maintain; you would have centralized account management; and your resources (printers, shared files, etc.) would be managed within each resource domain.

With all this is mind, here is your reading list:

Concerning trust issues outside the NT domain, Mole feels little qualified to comment.


NT as Bridge, continued

In the April 5th column, Gregor Samsa wrote in saying that his company wants to install an ISDN on-demand 128K line for connection to the Internet. Problem is, ISDN runs only on Ethernet and his company's LAN is Token Ring. What to do? Purchase an expensive Token Ring Router or bridge?

A certain telephone company recommended that he use a Netopia router. But there's the hitch: the Netopia router doesn't support Token Ring—it only supports Ethernet. While Gregor was talking with a Black Box techie, the techie suggested to Gregor that the following just might work:

Install an Ethernet NIC and a Token Ring NIC in one NT 4.0 Server. Connect the Netopia ISDN router to the Ethernet NIC and let NT act as the bridge between the hitch though; he doesn't know how to configure NT to support this arrangement. Routing and Remote Access (RRAS) should be installed on the same server that is multi-homed. Proxy Server should also be installed.

Mole responded that while NT could act as a router, it could not serve as a bridge.

Black Box Sr. Support Engineer Clif Eagle writes in, accusing your favorite omnivore of splitting hairs. Mole pleads nolo contendere. Clif's helpful e-mail follows:

"As you correctly pointed out, NT can route between two network cards but will not bridge between two network segments. However, in this situation, I believe Gregor was taking the response from the Black Box tech too literal. The tech was attempting to indicate that NT could serve as the interconnect, but as he indicated, he was not sure exactly how. The use of the term "bridge" was unfortunate (and misleading).

"In fact, we have tested this configuration in our LAN lab and it does work. All that is required is that IP forwarding be turned on (via control panel, network, <select the protocol>, routing tab). It is also helpful to insure that IP RIP (RIP for Internet Services) is also loaded. Of course all of the details of IP configuration must be attended to, different IP network numbers, subnet mask and default gateway. Remarkably, the same is true for IPX routing, enable IPX RIP routing and load RIP for nwlink IPX/SPX. In our tests we were able to log onto both an NT server and a Novell server through an NT server functioning as a router.

"Our philosophy in Black Box tech support is to help every customer to the best that we are able, even if that customer does not have a Black Box product. In this particular case the technician, even though he did not have all the details exactly correct, was able to point the customer in a viable direction. We feel that this is better than saying something like "Sorry, can't help you". "

Mole apologizes for glibness. Perhaps links to these useful articles will help repair his tattered karma:

  • 169548: Using Proxy Server with Routing and Remote Access

  • 140859: TCP/IP Routing Basics for Windows NT

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:

  • Your name

  • Your title

  • Your company

  • Your e-mail address

  • Your question/solution/compliment


Thanks to Chuck Anderson and Lon Collins.

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