NOVELL TECHNICAL INFORMATION DOCUMENT
TITLE: Deadlocks with Novell NetWare and Windows
DOCUMENT ID: TID021978
DOCUMENT REVISION: C
DATE: 11JAN95
ALERT STATUS: Yellow
INFORMATION TYPE: Symptom Solution
README FOR: NA
NOVELL PRODUCT and VERSION:
NetWare Client for DOS/MS Windows 1.2
ABSTRACT:
These document discusses updates that resolve problems when using
Windows 3.x or Windows for Workgroups 3.11 on a Novell network.
The symptom is a blank screen with a blinking underline curser in
the upper-left-hand corner of the screen and the workstation
hangs.
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DISCLAIMER
THE ORIGIN OF THIS INFORMATION MAY BE INTERNAL OR EXTERNAL TO
NOVELL. NOVELL MAKES EVERY EFFORT WITHIN ITS MEANS TO VERIFY
THIS INFORMATION. HOWEVER, THE INFORMATION PROVIDED IN THIS
DOCUMENT IS FOR YOUR INFORMATION ONLY. NOVELL MAKES NO EXPLICIT
OR IMPLIED CLAIMS TO THE VALIDITY OF THIS INFORMATION.
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ADDITIONAL CONFIGURATION
Third-Party Product and Version:
Windows 3.x
Windows for Workgroups 3.x
SYMPTOM
The symptom is a blank screen with a blinking underline cursor in
the upper-left-hand corner of the screen and the workstation
hangs. This may happen at any time while in Windows, launching a
DOS box, using a Windows application or exiting Windows.
The following is a list of causes/solutions that Novell has
isolated that can cause/remedy the symptom described above.
CAUSE
IPXODI.COM had a problem in SPX. During a retry, SPX would jump
to invalid memory causing an invalid opcode exception in v86 mode
only when SPX is being used. This usually manifests itself as a
reboot, hung machine, or blank screen with cursor in upper-left
corner.
CAUSE
LSL.COM had an issue that was GetStackECBPrescanIsPresent
destroyed the return Flag when an ECB was given. The symptom of
this problem would most likely manifest it self by a workstation
hang when using a protocol stack that expects to get an ECB from
the LSL under a heavy load.
CAUSE
LSL.COM also had a problem with the "Do Send for Windows" code
that needed a "Start and End Critical Section" call added.
CAUSE
An incorrect system configuration including memory management.
CAUSE
Any I/O, memory, or IRQ conflicts may cause this problem.
CAUSE
Using third-party device drivers or terminate-and-stay-resident
(TSR) programs.
CAUSE
Lan Card MLID driver's misuse of ECB buffers. (Update ODI MLIDs
as a standard trouble shooting tip)
CAUSE
Third party protocol stacks, such as TCPIP.
CAUSE
VIPX.386 is a Windows 3.x virtualization driver for IPXODI.COM
driver that was enhanced jointly by Novell and Microsoft. It
virtualizes requests to the globally loaded IPX driver. When a
request is made to IPX, VIPX will allocate a request buffer in
the system's global memory, copy the original request to the
global buffer and give the global request to IPX. When the
global request completes, IPX will call VIPX. VIPX will then
copy any results back to the original request buffer and call the
application that submitted the request.
CAUSE
Some Windows applications have been found to create the symptom
if when exiting Windows the application is running in the
background in a minimized state. If this occurs, close all
applications before leaving Windows.
CAUSE
There are occasions when using a WINSTART.BAT file (which is
created by the user and placed in the Windows directory) may also
cause Windows to hang when exiting Windows. Avoid a WINSTART.BAT
file if the symptom persists.
CAUSE
Microsoft has a patch called VTDA.386 for their Windows 3.1 VTD
(Virtual Timer Device). VTDA.386 is a obtainable from Microsoft.
Their BBS number is 206-936-6735 and the file to download is
WW0863.EXE.
*Note: Windows 3.1 was refreshed to 3.11. In the update, VTDA.386
is made available in the box. This patch is installed by default
if you select NetWare in the Windows SETUP option. This also
applies to Windows for Workgroups 3.11 users.
Version Compatibility with Dedicated IPX
----------------------------------------
Novell officially ceased maintenance on the dedicated IPX driver
(IPX.OBJ) version 3.10 dated 11-21-91. The last version of VIPX
to explicitly support that driver is 1.10. The current version
of VIPX supports IPXODI.COM only.
Packet Size Limitations
-----------------------
VIPX.386 will only virtualize packets that are 8000 (decimal)
bytes or less. Any DOS and Windows IPX or SPX applications that
use networks with a physical packet size greater than 8000 bytes
may not work with VIPX.386. For example, IBM Token Ring can be
configured to run with 16 KB packets. A request by a DOS or
Windows IPX application to send a 16 KB packet will be truncated
to 8000 bytes. On the other hand, any 16 KB packet that is
received by the LAN driver will be dropped because VIPX cannot
allocate a packet big enough to handle it.
Memory Manager Limitations
--------------------------
When a request is passed up from IPX, VIPX will immediately test
the request buffer to see if it is in global memory. If it is in
global memory, the request will be passed back down to IPX
without any virtualization. For example, a TSR loaded before
Windows is considered to be in global memory. If that TSR calls
IPX, VIPX will test the requests and pass them back down to IPX.
This is done because there is no need to virtualize requests that
are already global.
The use of UMA memory complicates the test for global memory.
There are two basic scenarios.
The first scenario is when a TSR has been loaded high before
Windows was loaded. In this case, IPX requests will come from
global UMA memory. VIPX will simply pass these requests back
down to IPX.
The second scenario is when a TSR is loaded high in a Windows
DOSBOX. In this case, IPX requests will come from local UMA
memory. VIPX will virtualize these requests.
Some memory managers test for global UMA memory and will work
properly under both scenarios. However, other memory managers
exist that do not work properly under Windows. With these
drivers, all local DOSBOX UMAs look as if they are GLOBAL UMAs.
In the case of the second scenario when a TSR calls IPX, VIPX
will test the request buffer and think that it is in global UMA
memory when it is really in LOCAL UMA memory. As a result, VIPX
will pass a local ECB to IPX without virtualization. The normal
result of this is a hung machine or data corruption.
SOLUTION
Novell strongly recommends that you update your dedicated IPX
driver with IPXODI.COM v2.12 or higher, included in VLMUP2 .EXE,
when using versions of VIPX later than 1.10.
Because of the problems with LSL.COM, Novell also recommends that
you update your LSL.COM to v2.05 or higher. This version is also
available in VLMUP4.EXE in the NOVFILES forum of Compuserve.
If you are using third-party memory managers and hang, do not
load TSRs using the IPX interface (including IPX itself) high.
Load these in conventional memory only.
Files Needed: Size Date Version Location Owner
================================================================
VIPX.386 23855 05-23-94 1.19 WINDR2.EXE Novell
IPXODI.COM 39353 10-31-94 3.01 VLMUP2.EXE Novell
LSL.COM 18313 10-11-94 2.14 VLMUP2.EXE Novell
VTDA.386 xxxxx xx-xx-xx x.xx WW0863.EXE Microsoft
Installation Instructions:
1. Rename or backup the old VIPX.386, IPXODI.COM, and LSL.COM
files.
2. Copy IPXODI.COM and LSL.COM to where the network board's
software is initialized.
3. Copy VIPX.386 to your WINDOWS\SYSTEM directory.
4. Virtualize the network board's IRQ in the [VIPX] section of
the SYSTEM.INI if using IBM LAN SUPPORT. (See Specialized
Configuration Parameters below for instructions)
5. Put TimerCriticalSection=10000 in the [386Enh] section of the
SYSTEM.INI.
6. Download, and implement the VTDA.386 driver from Microsoft as
documented in their README file.
7. Reboot the machine and load the ODI drivers.
8. Enter Windows.
Solution Specifics:
Specialized Configuration Parameters
------------------------------------
Under most circumstances, VIPX will work fine under the default
configuration. However, there may be some applications that
require custom configuration of the driver. This following is a
list of SYSTEM.INI parameters that can be used to configure VIPX:
[VIPX]
VipxMappingPages =[number of 4K pages] (default = 16)
VipxFailOverSizedPackets =[ON|OFF|TRUE|FALSE] (default = OFF)
VirtualizeIrq[0-F] =[ON|OFF|TRUE|FALSE] (default = OFF)
VIPX Parameters
VipxMappingPages
----------------
This is the number of pages that VIPX can use to globalize
requests to the global IPXODI.COM driver. VIPX is not absolutely
guaranteed to have all of these pages available at any one point,
because this is the requested number of pages for shared global
mapping that VIPX makes to the Windows VMM at initialization
time.
VipxFailOverSizedPackets
------------------------
This parameter tells VIPX to fail any requests that require more
than the maximum allowed globalization size. The actual maximum
will vary according to the media the user is using. The absolute
maximum is 8000 (decimal) bytes. With media that have smaller
packets than 8000 bytes, the maximum allowed size is the maximum
packet size that can be put onto the media.
VirtualizeIrq[0-F]
------------------
VIPX v1.15 or greater avoids a deadlock between the machine and
network board by virtualizing the network board's IRQ. With ODI
and dedicated IPX (IPX.OBJ) drivers, VIPX will automatically read
the configuration of the network board from the driver and
virtualize the selected IRQs. However, when using the IBM LAN
Support Program with SLANSUP.OBJ or LANSUP.COM, the LAN IRQ is
not readable from the driver. The only way to get this
information is to read the network board hardware itself. The
problem with doing this is that the hardware can be Token Ring,
PCN2 or Ethernet. VIPX must now be aware of many different
hardware configurations. Instead of this, VIPX requires the IBM
LAN Support user to specify the network board's IRQ in the [VIPX]
section of the SYSTEM.INI. IRQs range from 0 to F (hex). An
example is listed below:
[VIPX]
VirtualizeIrq2=TRUE
VirtualizeIrq3=TRUE
In this example, VIPX will virtualize both IRQ 2 and IRQ 3. VIPX
can virtualize up to four different LAN IRQs. The reason for
virtualizing multiple IRQs is to allow other LAN boards and
protocols to be installed on the same PC and prevent them from
deadlocking the machine. For example, you may have IPX running
through an NE2000 board on IRQ 3 and TCP/IP running through to an
IBM Token-Ring board on IRQ 2.
VIPX.386 v1.18 included the two following changes:
1. This file corrects a possible problem with virtualizing the
network board's interrupt line (IRQ) setting. The Virtualization
API returns a carry clear (OK) when the IRQ handle is 0. Now,
VIPX.386 will not virtualize the IRQ if the IRQ handle is 0.
Also a code was added to specify which VM (Virtual Machine)
"owns" a virtualized IRQ.
2. In VIPX.386, a comparison for the VM handle for an AES ECB
in the GLOBAL ECB was added. VIPX.386 also verifies the VM
handle for an AES ECB in a condition not previously considered.
VIPX.386 v1.19 includes the previous two changes plus three
additional changes:
1. A changed was made to force Windows applications to open
only long-lived sockets.
For example, if you ran a DOS BOX with RCONSOLE with v1.18, it
would allocate a short-lived socket; and if this DOS box was
terminated, VIPX would overwrite an area that caused Windows to
trap with a black screen and flashing cursor. VIPX v1.19 fixes
this issue.
2. This patch address an issue with a TSR (globally loaded)
that needs to open sockets after Windows is loaded. Right now,
v1.18 closes all sockets, opened after Windows is loaded, when
exiting Windows.
A fix was made to check for the KeepLongLivedSocketsOpen
parameter. This parameter is set to OFF by default. If this
parameter is set to ON when an Open Socket operation is issued
from V86 mode, the socket will be considered global and will not
be closed when exiting Windows. The syntax to change the default
from OFF to ON needs to be added to the end of SYSTEM.INI file as
follows:
[VIPX]
KeepLongLivedSocketsOpen=[TRUE|FALSE|ON|OFF] default=FALSE
3. This patch resolved an issue related to Virtualizing LAN
IRQs.
For example, when exiting enhanced mode Windows back to DOS,
sometimes the cursor will flash in the upper left hand corner and
not return back to the DOS prompt.
With this update the releasing of a Virtualized IRQ is restored,
allowing COMMAND.COM to be reloaded, and the SYSTEM to return to
the DOS prompt.
TimerCriticalSection
--------------------
As of version 1.15 of VIPX, TimerCriticalSection is required to
be set on. The recommended setting is as follows:
[386Enh]
TimerCriticalSection=10000
The reason for this parameter is to avoid a deadlock with the LAN
IRQ Virtualization code. See "VirtualizeIrq[0-F]" section.
================================================================
LSL.COM
Commandline Switches:
Valid switches: U, F, ?, H, C=
Only the "U, ?, C=" are documented in the help.
U Used to unload LSL.
? Used for Help.
F Used to force the unload.
H Used as an equivalent to "?" switch, and is used by
many of Novell's other utilities.
C= Used to change the path or filename of the configuration
file. The "C=" switch is the only two-letter switch that is
valid, Custom Configuration Files. When using the "C="
command-line switch, the LSL first tries the [path]\filename as
given. If the file is not found, then the filename is searched
for in the directory where the LSL was loaded from; and if it
still cannot be found, it looks in the current working directory.
If all these efforts fail, then the LSL reverts back to looking
for a "NET.CFG" file in the directory where the LSL was loaded
from then in the current working directory. The filename is
considered valid even if the path was incorrect. After parsing
the Configuration file, the LSL displays the relative path of
the Configuration file that was parsed.
================================================================
IPXODI.COM
Command line Switches:
Valid switches: /?, /D, /A, /C=, /U, /F
? Used for help screen.
D Used for Eliminate Diagnostic Responder; reduces size by 3
KB.
A Used for Eliminate Diagnostic Responder and SPX; reduces
size by 9 KB.
PLEASE NOTE: Disabling SPX will mean that SPX applications (such
as RPRINTER, BTRIEVE, RCONSOLE, or NetWare for SAA STRNRTR) will
not be supported on this workstation.
C= Used to change the path or filename of the configuration
file. "C=" is the only two letter switch that is valid. If the
*.CFG file used does not exist a message will be displayed that
the standard NET.CFG file will be used instead.
U Used to unload.
F Used to force the unload.
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