Bug 4728 - NFS and Linker (ld) executable file corruption problem from RHL 6.0 (2.2.5-15 or 2.2.11) to AIX 4.2.1
Summary: NFS and Linker (ld) executable file corruption problem from RHL 6.0 (2.2.5-15...
Keywords:
Status: CLOSED NOTABUG
Alias: None
Product: Red Hat Linux
Classification: Retired
Component: dev
Version: 6.0
Hardware: i386
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Michael K. Johnson
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 1999-08-26 20:16 UTC by david
Modified: 2008-05-01 15:37 UTC (History)
1 user (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 1999-09-21 21:30:13 UTC
Embargoed:


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Description david 1999-08-26 20:16:10 UTC
Hardware: DELL Optiplex GX1, 256Mb RAM, running RH Linux 6.0
          using both the stock 2.2.5-15 kernel and the
          latest 2.2.11 kernel.
          IBM RS6000 3AT running AIX 4.2.1

1) RS6000 serves an NFS file system to the Linux box.
NFS file system contains Fortran source code for a
modelling program.

2) Compile the source code in 4 scenarios - on the linux box
using the PGI fortran 90 compiler and ECGS for one .c file.

   a) Source compiled to .o files on NFS filesystem.
      Executable written to NFS file system.

   b) Source compiled to .o files on NFS file system.
      Executable written to local filesystem on Linux box.

   c) Source compiled to .o files on local file system.
      Executable written to local file system.

   d) Source compiled to .o files on local file system.
      Executable written to NFS file system.

3) Results:

   a) All of the .o files compiled to either the local
      or NFS file systems compare as Identical.

   b) Executables that are written on the NFS file system
      do NOT work. They generate an error:
      Memory Fault (core dump).

   c) Executables that are written to the local file
      system from either local or NFS .o files work
      correctly.

   d) A byte by byte comparison of the executable files
      shows that they only differ by about 12k bytes out of
      4Mb. The difference is that a few zeroes have
      crept into the corrupt executable image. Usually just
      one or two here and there that shift the binary
      code by a byte or two for sections of the executable.
      The whole 12k of appears to be caused by a handful
      of corruptions where these extra zeroes offset the
      executable code for a section.

4) Conclusion:

      It appears as if the linker is having some sort
      of problem with writing a complete executable on
      an NFS mounted file system. Compile and link to
      a local drive from either local or NFS .o works
      correctly. Compile and link to an NFS file system
      from either local or NFS .o files generates a
      corrupt executable.

      This could be related to the IBM NFS implementation -
      but at the moment looks more like a linker/NFS
problem       of some sort.

      At least one other report of a problem with similar
      symptoms on similar hardware has been reported on
the        comp.os.linux.* newsgroups but no solution seems
to be
      available.

Thanks for any help or suggestions - this problem makes
it difficult to use NFS in this case.

Cheers,

David

Comment 1 Jeff Johnson 1999-08-27 14:20:59 UTC
The problem is not with the linker but with NFS, probably on the
server machine. Have you checked for AIX patches? There's a similar
problem on Solaris, and the fix was to apply a patch to the Solaris
server.

Comment 2 Michael K. Johnson 1999-09-20 16:53:59 UTC
I think I've heard of a related problem that was resolved by a patch
to AIX.  I think that if you don't need file locking, you can tell
AIX to export the filesystem to Linux as an NFSv2 filesystem to get
the same result.

Comment 3 Michael K. Johnson 1999-09-21 21:30:59 UTC
As Alan has emailed that this is definitely a known bug in AIX,
we're closing it.


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