Date:  June 10, 1987
Number:  188

Title:  PROBLEMS WITH ADVANCED NETWARE V2.0A FILE & RECORD      
        LOCKS

This bulletin is applicable to the following:

          Advanced NetWare 86 v2.0a
          Advanced NetWare 286 v2.0a
          Nondedicated NetWare 286 v2.0a
          SFT NetWare 286 Level I v2.0a
          SFT NetWare 286 Level II v2.0a
          SFT NetWare 286 Level II with TTS v2.0a

PROBLEM

Users of applications which do large numbers of file and/or record locks
may experience intermittent General Protection Interrupts (GPIs) on the file
server.  Usually this problem exhibits itself on ARCNET* compatible and other
networks that are slower than 3 Mbps.  The frequency of the GPI increases
as the number of operating workstations increases.  With six workstations,
the error usually occurs within 20 minutes.  Upgrading the system to a faster
LAN topology, such as Ethernet, usually causes the problem to cease.

Initially, the problems were found by users of Softcraft's Btrieve, which
performs large numbers of physical record locks.  Potentially, the problem
could also exhibit itself with any other lock intensive application.

CAUSE

This problem was found to be caused by two bugs in the lock code in
the operating system.  Although related, each of these two bugs would cause
the file server to GPI at different places.  The bugs would exhibit themselves
only when intensive record and/or file locking were performed on a lower
performance network.

SOLUTION

Patches that will correct the two bugs discussed above have been
formulated for the various NetWare operating systems.  A program has been
written that will automatically implement the patches to the NET$OS.OBJ file
of the following operating systems:

          Advanced NetWare 86 v2.0a
          Advanced NetWare 286 v2.0a
          Nondedicated NetWare 286 v2.0a
          SFT NetWare 286 Level I v2.0a
          SFT NetWare 286 Level II v2.0a