problem with advfs and a particular IO pattern

From: Steve Feehan (sfeehan@sbb.uvm.edu)
Date: Fri Nov 05 2004 - 12:06:13 EST


Hello. One of my users has a program that writes fixed
length records at random locations in a file. The original
program is Fortran, so I wrote a C program (I don't grok
Fortran, and my C is not much better) to reproduce the error:

  http://sbb.uvm.edu/~sfeehan/record.c

When the record length is > 640 bytes, after a few hundred
writes he get's an IO error.

This problem only happens on local AdvFS file systems. It is
is not limited to a particular device (the system has several
internal disks and also connected to a MA8000 SAN) and
does not occur on NFS mounted file systems.

The program runs fine on other Tru64 systems, on both local
and NFS file systems EXCEPT if the NFS file system is exported
from the problematic host. Make sense?

Any thoughts or suggestions? Thanks!

-- 
Steve Feehan


This archive was generated by hypermail 2.1.7 : Sat Apr 12 2008 - 10:50:11 EDT