Re: PSQL control center crashes PSQL engine.

#1

You could report it to Pervasive but it is not really a Pervasive
issue. The Windows OS will only allow a single process to allocate
2GB of memory and reserves the other 2GB for itself. More accurately
the process is limitted to 2GB of "Address Space" not allocated
memory, and yes there is a technical difference betweent the two.

Certain versions of Windows do allow a process to allocate mroe than
2GB with a special setting. For more details search for /3GB on
www.microsoft.com.

If you truly want to use all the memory in your server and you have
more than 2GB you can alwayr run with these settings.

1) Cache Size ~500MB (give or take 100MB or so)
2) Max MicroKernel Memory Usage = 0
3) System Cache = YES.

What this does is moves some of the caching to the OS level. While
the OS is not as good at doing database caching as the database engine
it is not restricted to 2GB so can use all the memory the database
engine is not using and still avoids doing physical disk IO.

Leonard

On 14 Feb 2006 10:02:14 +0100, "Karl A. Sørensen"
<kas (AT) kamstrup-ems (DOT) no> wrote:

Quote:

We have the following environment:
Server:
2xXeon processor with 4GM memory.
Windows 2003 server, service pack 1.
PSQL 9.10.

Clients:
Win XP SP2.

I have set up our PSQL server to use almost 2 GB cache. Total allocated
memory on the server is then a bit more than 2GB.
In this situation, if we do the following on a client, the PSQL server
crashes:
1. Open PSQL control center.
2. Select a database.
3. Select a table.
4. Right click on the table, and select properties. The PSQL server crashes.

This is the error from PVSW.LOG on the server:
"02-10-2006 13:48:10 W3COMSRV 00000D30 NTDBSMGR.EXE LONGUM2
E VirtualAlloc(lstnBuf) error=8."

Attached is a bitmap from the error appearing on the server.

If we reduce the cache size on the server so that the total allocated memory
is below 2GB, this works fine.

Is this a known problem, or should it be reported to Pervasive??

Regards
Karl

#2

To see how much "Address Space" the OS believes a process to have you
need to use Perfmon.exe.
Add a counter for "Process" -> <process name>, ntdbsmgr.exe is the
Pervasive.SQL engine -> "Virtual Bytes".

The descriptions describe the different counters as slightly different
then I expected. "Virtual Bytes" appears to be the "address space"
allocated by the OS. "Working Set" appears to almost be the real
memory used and "Private Bytes", well your guess is as good as mine
based on the description.

If the perfmon process "Virtual Bytes" counter ever hits 2GB then that
is when the problems start happening, For Pervasive people can
usually eek out 1.7 GB of cache, but it really depends on other usage,
e.g. how many data sessions, how many files are open, SQL engine
usage, ...

Leonard

On 17 Feb 2006 08:55:38 +0100, "Karl A. Sørensen"
<kas (AT) kamstrup-ems (DOT) no> wrote:

Quote:

Thanks!
I had a suspicion that this was the problem, but since I had allocated 1.7GB
to the Pervasice cache, I thought I was below the limit. Total allocated
memory on the server (all processes) was just above 2GB.

Regards
Karl

"Leonard" <lharvey (AT) austin (DOT) rr.com> wrote in message
news:8359v1plkvb0f36t1ep8kt2ivg1cbf1cvr (AT) 4ax (DOT) com...
You could report it to Pervasive but it is not really a Pervasive
issue. The Windows OS will only allow a single process to allocate
2GB of memory and reserves the other 2GB for itself. More accurately
the process is limitted to 2GB of "Address Space" not allocated
memory, and yes there is a technical difference betweent the two.

Certain versions of Windows do allow a process to allocate mroe than
2GB with a special setting. For more details search for /3GB on
www.microsoft.com.

If you truly want to use all the memory in your server and you have
more than 2GB you can alwayr run with these settings.

1) Cache Size ~500MB (give or take 100MB or so)
2) Max MicroKernel Memory Usage = 0
3) System Cache = YES.

What this does is moves some of the caching to the OS level. While
the OS is not as good at doing database caching as the database engine
it is not restricted to 2GB so can use all the memory the database
engine is not using and still avoids doing physical disk IO.

Leonard

On 14 Feb 2006 10:02:14 +0100, "Karl A. Sørensen"
kas (AT) kamstrup-ems (DOT) no> wrote:

We have the following environment:
Server:
2xXeon processor with 4GM memory.
Windows 2003 server, service pack 1.
PSQL 9.10.

Clients:
Win XP SP2.

I have set up our PSQL server to use almost 2 GB cache. Total allocated
memory on the server is then a bit more than 2GB.
In this situation, if we do the following on a client, the PSQL server
crashes:
1. Open PSQL control center.
2. Select a database.
3. Select a table.
4. Right click on the table, and select properties. The PSQL server
crashes.

This is the error from PVSW.LOG on the server:
"02-10-2006 13:48:10 W3COMSRV 00000D30 NTDBSMGR.EXE LONGUM2
E VirtualAlloc(lstnBuf) error=8."

Attached is a bitmap from the error appearing on the server.

If we reduce the cache size on the server so that the total allocated
memory
is below 2GB, this works fine.

Is this a known problem, or should it be reported to Pervasive??

Regards
Karl

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Re: PSQL control center crashes PSQL engine.

comp.databases.btrieve comp.databases.btrieve

Re: PSQL control center crashes PSQL engine. - 02-16-2006 , 09:06 AM

Re: PSQL control center crashes PSQL engine. - 02-17-2006 , 08:31 AM