NT, DBF's, Indexes and Corruption detected or Access Denied 
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 NT, DBF's, Indexes and Corruption detected or Access Denied

Just for the record (Googles that is):

I was testing some network file stuff with my NT 4.0 sp6a machine
accessing a Win 98 machine and was getting very slow response, and
quite soon a "Corruption Detected" error or a DOS error 5 (access
denied). When I was not using indexes it seemed to run fine. Both NTX
and CDX indexes gave the same results - using the 5.3b version of
Clipper. Running the same test from the Win98 box to the NT box was
fine. A Win2000 (sp2) box as a server was fine.

After a LOT of research on MSDN and messing around I have discovered
that if you replace the file NETBT.SYS (for sp6a) in
\WINNT\system32\drivers with the one from sp5 then all is well (YMMV).
Thanks to Eric Jacobowitz for this insight. I was only running TCP/IP
and I think it is possible that if NETBEUI was installed then I
wouldn't have had a problem (I don't *know*).

See MSDN :
Performance Improvement for Redirector/Server Connections Involving
Small File Operations

I assume the rapid locking and unlocking of parts of the index that
the RDDs perform during access causes a great number of very small

I followed up this article:

Slow Network Performance with Service Pack 4, 5, 6, or 6a

but did not make any headway with this line of enquiry or obtaining
the hotfixed RDR.SYS that they mention. It would be nice if there was
a sp7 but, alas, it shall never be.

I am sure it is not a good thing to go around mixing and matching
files from service packs but if you are stuck (I was) then I HTH.

Please also check out Klas Engwalls oft repeated advice about
CachedOpenLimit, EnableOplocks and AutoDisconnect values in the
registry if using NT, 2000 and XP as a server and UseLockReadUnlock,
UseOpportunisticLocking and UtilizeNtCaching if using NT, 2000 and XP
as clients.

Alex Strickland
sscc zat mweb pt co pt za

Sat, 15 Jan 2005 18:17:54 GMT  
 [ 1 post ] 

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