Re: 2.4 NFS file corruption

[Trond Myklebust]

>>>>> " " == Roland Kuhn <[e-mail]> writes:

     > Dear experts!  I'm seeing very strange file corruption, with
     > parts of the data (most of the bytes, actually) being correct,
     > but some being 0x00 and others (few) being something else. The
     > strangest thing however is that this affected exactly the
     > complete first 4kB page of the file.

     > The server and clients run CERN RedHat 7.3.2, which is based on
     > RedHat 7.3 and has a 2.4.18 kernel with patches upto the
     > 2.4.21-pre5 range. If you need the list of patches I can look
     > it up and will happily supply it.

AFAICS, the CERN 2.4.18-27.7.x doesn't appear to have any NFS patches
in it beyond the standard 2.4.18 + the IRIX patch (i.e. it is
identical to the RedHat kernel as far as NFS is concerned).

As such it is missing a good deal of NFS client bugfixes, including
the close-to-open patches which are important when you are updating
files centrally on a server.

It probably isn't the cause of problems here though (if I read the
section below correctly).

     > 1) copy the file onto the server's exported directory
     > 2) create a symlink to it from the same directory
     > 3) execute the file
     > 4) process crashes, gets restated (repeatedly, because of
     >    corruption)
     > 5) machine is rebooted, everything works fine for several hours
     > 6) restart at 4)

     > While in this circle, the file was overwritten several times
     > with updated versions.

You are updating an executable while the clients are running it??? 
Bad! That is not meant to work...

Cheers,
  Trond