This month's Tricks & Traps includes tips on some familiar problems. Send us your tip. If we print it, we'll send you a Tricks & Traps coffee mug. Visit Bob Chronister's online Tricks & Traps at http://www.winntmag.com/Forums/.
Tip 1 comes from David Brandt at Exabyte: With Windows NT 3.5, you can use the Registry Editor to disable the Printing Notification network dialog that the Print Server Spooler sends for a printer error or when the spooler completes or deletes a print job. (The option to disable this dialog is not available with NT 3.1 or NT Advanced Server 3.1.)
WARNING: Using the Registry Editor incorrectly can cause serious, systemwide problems that can require you to reinstall NT to correct them. You have no guarantee that you can resolve problems resulting from the use of Registry Editor. Use this tool at your own risk.
- Start Registry Editor.
- From the HKEY_LOCAL_MACHINE subtree, go to subkey \SYSTEM\CURRENTCONTROLSET\CONTROL\PRINT\PROVIDERS.
- From the Edit menu, select Add Value.
- In the Value Name field of the Add Value dialog, type NetPopup.
- Select REG_DWORD for the Data Type.
- Select OK.
- In the Dword Editor dialog, type 0 in the Data field.
- Select OK.
- Exit the Registry Editor.
- For the new setting to take effect, restart the Spooler service from the Services portion of the Control Panel.
This setting applies to all printers on a particular print server--you can't set the option to disable the dialog on a per-printer basis. If you turn off the print notification for a printer connected directly via a parallel and serial port, any printing problems associated with that printer will appear as an error dialog on the server. Printing will not resume even if you identify and fix the error; you need to log on to the server and select Retry or Cancel in the error dialog. This situation doesn't affect printers connected through the network.
Tip 2: In the March issue of Windows NT Magazine, I stated that you can use NET CONFIG SERVER /AUTO DISCONNECT:-1 to turn off AutoDisconnect. A better way is to turn it off in the Registry (with a value of FFFFFFFF) because the command line incorrectly tells NT to write all its autotuning parameters, and not just the AutoDisconnect value, to the Registry. Screen 1 shows where to add the value to turn off AutoDisconnect.
- Open the Registry Editor.
- Go to key HKEY_LOCAL_MACHINE\SYSTEM\CURRENTCONTROLSET\SERVICES\LANMANSERVER\PARAMETERS.
- Add value AutoDisconnect.
- For REG_DWORD, add value FFFFFFFF.
Tip 3:I also have a correction to my tip about the Adaptec 2940 in the March issue. To use the Adaptec 2940 with Phoenix BIOS, the 2940 must use at least BIOS version 1.23. The toll-free number I provided is no longer available except for automated tech support. To speak directly to a technician, call 408-934-7274.
I read your tip on Scheduler services; please expand on it for the following situation. I have a Novell and NT server network (on the same segment). I want scheduled backups of the Novell and NT server volumes. I can perform the backups manually, but if I try to back up the NT server or the Novell volumes, the Scheduler process starts and writes, "no files found to back up," into the log. I've tried several methods to make the backup work.
This problem occurs when you run Scheduler under the system account. Such services use null session support when they run under the system account. Unfortunately, null session support doesn't provide adequate security credentials for scripts performing commands such as NET USE. To avoid this problem of inadequate security, don't use the system account. Instead, configure services such as Scheduler and custom applications with user-specific accounts. These accounts have user-level security based on a specific account and its associated password.
I see users complaining about insufficient memory messages for the server service on systems with lots of RAM and hard drive space. What causes this?
You can alter some settings on the server to maximize the server service. Several Registry parameters control this service under
HKEY_LOCAL_MACHINE\SYSTEM\CURRENTCONTROLSETSERVICES\LANMANSERVER\PARAMETERS. These parameters are
MinFreeConnections REG_DWORD
Range: 2 to 5 items
Default: (depends on configuration)
This parameter specifies the minimum number of free connection blocks maintained per endpoint.
MinFreeWorkItems REG_DWORD
Range: 0 to 10 items
Default: 2
This parameter specifies the minimum number of available receive work items the server needs to begin processing a potentially multiblock Server Message Block (SMB) request. Increasing the value for this parameter ensures that work items are available more frequently for nonblocking requests, but also increases the likelihood that the server will reject blocking requests.
MinKeepSearch REG_DWORD
Range: 5 to 5000 seconds
Default: 480
This parameter specifies the minimum time the server will keep incomplete MS-DOS searches, even if the server needs more search entries. This parameter matters only when the server nears the maximum number of open searches.
MinLinkThroughput REG_DWORD
Range: 0 to infinite bytes per second
Default: 0
This parameter specifies the minimum link throughput the server allows before it disables raw and opportunistic locks for this connection.
MinRcvQueue REG_DWORD
Range: 0 to 10 items
Default: 2
This parameter specifies the minimum number of free receive work items the server needs before it begins allocating more. Increasing this parameter's value helps ensure that work items will be available, but a value that is too large is inefficient.
The following sequence will usually eliminate the insufficient memory message on a server:
- Start the Registry Editor (REGEDT32.EXE in the \SYSTEM32 directory).
- Go to the key HKEY_LOCAL_MACHINE\SYSTEM\CURRENTCONTROLSET\SERVICES\LANMANSERVER\PARAMETERS.
- Add MinFreeConnections
- Type: REG_DWORD
- 5
- Exit Registry Editor.
- Start Control Panel/Network.
- Highlight Server Service, and select Configure.
- Select Optimization, maximize throughput for file sharing.
Why does a server have a workstation service?
Consider the workstation service as being a redirector. Instead of sending a file to a printer or across a modem, the workstation service sends it to the network.
Can I eliminate the pop-up messages that make me respond?
You can turn these messages off. Then you need to look in the event log to find out whether a problem exists. With the Registry Editor (always back up the Registry before editing), go to HKEY_CURRENT_USER \SOFTWARE\MICROSOFT\WINDOWS NT\CURRENTVERSION\WINDOWS. Screen 2 shows where to add the value to turn off the pop-up messages.
ErrorMode REG_DWORD
Range: 0, 1, or 2
Default: 0
This entry controls the behavior of hard error pop-up
messages. Possible values are
Mode 0: Serializes errors and waits for a
response
Mode 1: Excludes system errors the system writes to the event log.
Normal errors still show up
Mode 2: Logs the error to the event logger and
returns OK to the hard error without displaying pop-up messages
In all modes, the system writes system-originated hard errors to the system log. To turn off pop-up messages, set the value to 2.
I understand the size of a bootable hard drive is limited to 2GB. The 32-bit environment supports much larger drives, so why is this the limit?
When you install NT, it runs into the File Allocation Table (FAT) limit of a 2GB boot partition. To eliminate the size limit, connect the drive to another system running NT and format the drive as an NT File System (NTFS). Now you can connect the drive to the new system and install NT.
I'm confused by NT's security model. What are domains and how do they differ from workgroups?
A domain is a logical grouping of clients (workstations and servers) with at least one server acting as a domain controller that stores the master user and group database. When you log on to a domain, you are logging on to a centralized unit that maintains the security of the network. Alternatively, a workgroup maintains security locally rather than centrally. Because only domain controllers handle security, a domain lets individual systems run with less overhead than a workgroup. For more information on this subject, see "Domains and Workgroups," by Mark Minasi in the April issue of Windows NT Magazine, and see "Domains, Trust Relationships, and Groups," by Ed Tittel and Mary Madden in the June issue.
I keep seeing references to Microsoft SMS. What's SMS and what does it do?
Systems Management Server (SMS) helps domain administrators manage the domain. It's a database maintained in SQL Server. Each workstation is a client to an SMS server (which the system unfortunately defines as an SMS Domain). Four basic uses of SMS are hardware inventory across a domain; software inventory across a domain; software distribution across a domain; and diagnostics, network monitoring, and remote control.
Although immature, SMS is an ambitious attempt to move into enterprise control. Rumor has it that Microsoft will incorporate SMS with Computer Associates' Unicenter in a future release. For more information on SMS, see "SMS: Inventory Your Desktop Systems," by Spyros Sakellariadis in the May, June, and July issues of Windows NT Magazine.
What are SMP and MPP computers?
SMP stands for symmetrical multiprocessing, and MPP stands for Massively Parallel Processors, which NT doesn't achieve very well. These terms usually apply to UNIX machines.
Adding processors in an SMP computer increases power but not necessarily speed--the load carried increases. As a rough analogy, I think of an SMP box as a diesel truck rather than a race car with the fastest CPU available.
On the PC side, two major obstacles challenge the successful implementation of SMP: memory coherence and memory sharing. In design, memory coherence is when each processor accesses the same bytes at the same memory address. In practice, this coherence is difficult to achieve. Memory sharing is also a serious problem. Several vendors are attempting to make each CPU aware of what another CPU has in its onboard cache. Some strategies involve including bus snooping or switched memory models. Whereas bus snooping happens all the time, switched memory models are very expensive. With bus snooping, a CPU writes known, cached address values to system memory before a bus cycle completes. A switched memory model is when a CPU requests and accesses a memory location and a second CPU cannot access this location until the first releases it. Most systems use bus snooping.
A scheduler handles the basic strategy of SMP. The scheduler assigns code to run on the first available CPU. This scenario implies that an inactive CPU will receive the next piece of code (basically, a thread) for execution. In this manner, the system distributes processing symmetrically across the processors. The overhead may take away some speed, but the power of the architecture is impressive.
I'm planning a network and need some clarification of terms. What do the Primary Domain Controller (PDC) and Backup Domain Controller (BDC) synchronize? What's the difference between a global and local group?
The PDC and BDC exchange security information. Anyone who is familiar with and uses logon scripts will be disappointed to know that the PDC doesn't pass a logon to BDC. To do this, you need to replicate the script directories (SYSTEM32\RE\IMPORT\SCRIPTS).
Global groups are groups you can use in other domains; however, until you add global groups to local groups, the global groups are powerless. Local groups provide functionality, and global groups provide transportability. For more on groups, see Ed Tittel's and Mary Madden's "Domains, Trust Relationships, and Groups," in the June issue of Windows NT Magazine.
