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From: stern@polygen.UUCP (Hal Stern)
Newsgroups: comp.unix.ultrix
Subject: cc, ld, ar over NFS
Message-ID: <8597@felix.UUCP>
Date: Fri, 9-Oct-87 14:59:58 EDT
Article-I.D.: felix.8597
Posted: Fri Oct  9 14:59:58 1987
Date-Received: Mon, 12-Oct-87 19:27:55 EDT
Sender: zemon@felix.UUCP
Organization: Polygen Corp., Waltham, MA
Lines: 48
Approved: zemon@felix.UUCP (Art Zemon)

we have a heterogeneous network of Suns and VaxStations, all with
NFS.  the interesting part of our network is:
	machine polygen, Sun 3/160, two eagles running Sun 3.2
	machine figeac, Vaxstation II GPX, running Ultrix 2.0-1

polygen exports /usr/polygen, figeac exports /usr/figeac.  both
mount the other's disks.  figeac's /etc/fstab entry for polygen's
disk looks like:
	/usr/polygen@polygen:/usr/polygen:rw:0:0:nfs:bg,soft:
/usr/polygen is the "g" partition of a fujitsu eagle.  figeac has 
three RD-53s.

our local source code control system keeps all sources for a product
in a single directory tree, using subdirectories for each specific
machine on which it gets compiled.  in the case of product XX, the
source code lives on the Sun disk, in /usr/polygen/XX.  

here's the problem: when the Vaxstation figeac begins to compile
the source for XX, using the files mounted via NFS, various object
files get mangled.  the errors we usually see are from ar:
	"mangled string table"
	"foo.o: bad format"

i have run nm on the corrupted object files, and have found that
many of them have text and bss points with no names.  it is
very hard to reproduce this problem, although it appears to happen
when we combine many large .o files into a single .a archive.
the individual objects appear to compile OK, but when the archiver
runs it complains of corrupted files.  it appears that both cc and
ar are at fault; i have stopped the compilation and inspected .o 
files to find that they have been corrupted.

we have temporarily solved the problem by separating the source trees
and running the compile locally (and it completes without problem).  

does anyone else have this problem?  could this be related to an NFS 
timeout problem?  the compile completes OK on local disks but fails 
on NFS-mounted disks, which would lead me think it is NFS-related.

replies by e-mail will be summarized, with results.  thanks.

--hal stern
  polygen corporation
  200 fifth avenue
  waltham, ma  02254
  (617) 890-2888

  {bu-cs, princeton}!polygen!stern