[CentOS] File system cache corruption with CentOS4?

Wed Dec 5 15:42:56 UTC 2007
James Pearson <james-p at moving-picture.com>

Just wondering if anyone else has come across an issue where files 
cached in memory appear to become 'corrupted' - for example, on one 
workstation, I've just had the issue:

# yum
Traceback (most recent call last):
   File "/usr/bin/yum", line 4, in ?
     import yum
   File "__init__.py", line 36, in ?
   File "config.py", line 34, in ?
   File "repos.py", line 29, in ?
   File "repoMDObject.py", line 18, in ?

strace'ing the process didn't show up anything obvious

However, I ran a simple process that just grabs memory - which has the 
side effect of 'flushing' caches from memory.

After, doing this, yum ran fine ...

I've seen this issue quite a few times with various applications and on 
different machines - and flushing the caches in the way fixes the issue ...

OK, it could be a real memory problem, but given the number of times I 
see this issue, on machines that are fine otherwise, it makes we wonder 
if it could be a cache issue ...

All the machines are running a CentOS4.4 based kernel - (I plan to move 
to a CentOS4.6 based kernel when it is out). The kernel is not a vanilla 
CentOS4.4 kernel - it includes a few small non-standard patches - but 
nothing that touches the VFS layer (AFAIK). The issue occurs on i686 or 
x86_64 boxes. All machines have at least 4GB of memory. They also use 
the nVidia binary-only module.

Anyone seen issues like this?

Thanks

James Pearson