Possible Kernel issue (?): "handed out a duplicate delegation" errors

[Nathan Patwardhan]

Hello,

This issue has suddenly cropped up under SLES 10 w/the following specs:
  - x86_64
  - kernel 2.6.16.53-0.16-smp
  - nfs-utils-1.0.7-36.26
  - nfsidmap-0.12-16.17

Under certain circumstances (that we're still currently trying to
determine), the system will end up under a tremendously high load
(over 350!) and will no longer be able to function.  Reads, writes,
and killing processes will all fail and the only recourse is to
reboot.  When this happens, we see the following in /var/log/messages:

  nfs_inode_set_delegation: server 172.17.4.50, handed out a duplicate
delegation!
  sql[4874]: segfault at 000000006320201c rip 00000000f7e2d9a9 rsp
  00000000ffb3ff78 error 4
  sql[4881]: segfault at 000000006320201c rip 00000000f7ebd9a9 rsp
  00000000ff975da8 error 4
  nfs_inode_set_delegation: server 172.17.4.50, handed out a duplicate
delegation!
  nfs_inode_set_delegation: server 172.17.4.50, handed out a duplicate
delegation!
  nfs_inode_set_delegation: server 172.17.4.50, handed out a duplicate
delegation!
  nfs_inode_set_delegation: server 172.17.4.50, handed out a duplicate
delegation!
  nfs_inode_set_delegation: server 172.17.4.50, handed out a duplicate
delegation!
  nfs_inode_set_delegation: server 172.17.4.50, handed out a duplicate
delegation!
  nfs_inode_set_delegation: server 172.17.4.50, handed out a duplicate
delegation!
  decode_op_hdr: reply buffer overflowed in line 2071.<4>decode_op_hdr:
  reply buffer overflowed in line 2071.<4>call_verify: auth check failed
  call_verify: auth check failed

Has anyone else seen this before?  The message seems obvious, but I
want to make sure that it's not a red herring.

If the fix is to install updated libraries or a kernel,  we prefer not
to install custom RPMs for SLES 10 and instead to wait for packages to
be installed via online_update.

Note that we've only seen this problem under SLES 10 and not under
Ubuntu Gutsy or Debian Etch.

-- 
Nathan Patwardhan