On 2005 Mar 2 , at 18.11, Peter W. Draper wrote:
> like the old NFS and HDS MAP_SHARED problem, namely HDS files that are
> mapped over NFS are getting corrupted (don't think we've seen this
> since
> the 2.2 days).
I didn't know you could mmap over NFS (I assume HDS_MAP does use mmap,
or am I getting the wrong end of the stick), but it sounds verrrrry
precarious. My guess would be a funny, not in the kernel, but in the
nfsd. I found a mention of a broadly similar problem at
<http://lists.samba.org/archive/ccache/2003q3/000038.html> which
mentioned a no_subtree_check NFS option -- would that sort of thing be
worth looking at? Other messages suggested that things break horribly
when you use mmap+locking+nfs, but I imagine you've found all of these
pages already.
Would it make sense to use instead a heuristic that told libhds to mmap
a file if local, but not if NFS mounted?
Not a very helpful response, I'm afraid....
Norman
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Norman Gray : Physics & Astronomy, Glasgow University, UK
http://www.astro.gla.ac.uk/users/norman/ : www.starlink.ac.uk
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