MMapFile: File locking failed with error code 37

[Jerry Feldman]

We are having some issues with RHEL 5.2 NFS.  If I run the program on a=20
system with local disks, everything works fine, but if I run it on an=20
NFS mounted drive, I get this error. I've tried this on a couple of=20
different systems in my office, on a couple of different directories=20
including my home directory. I have no problem creating files on any of=20
the systems. This problem did not show up when we were running RHEL 4=20
Update 6.
This is a ps of the system that exports nfs:
 126 ?        S<     0:00 [kblockd/0]
  127 ?        S<     0:00 [kblockd/1]
  128 ?        S<     0:00 [kblockd/2]
  129 ?        S<     0:00 [kblockd/3]
  130 ?        S<     0:00 [kblockd/4]
  131 ?        S<     0:00 [kblockd/5]
  132 ?        S<     0:00 [kblockd/6]
  133 ?        S<     0:00 [kblockd/7]
20650 ?        S      0:00 [lockd]

This is from one of the systems that import the NFS volumes:
   96 ?        S<     0:00 [kblockd/0]
   97 ?        S<     0:00 [kblockd/1]
  6272 ?        S      0:00 [lockd]


Here are the actual error messages:
mmap file locking error: No locks available
MMapFile: File locking failed with error code 37
MMapFile: '/home/gaf/from04.dat.0' has been locked by another process.
MMap file creation failed for file /home/gaf/from04.dat.0

The program that locks the data was written in C++ under a 2.6.9 32-bit=20
kernel where the execution environment is RHEL 5.2  x86_64 with a=20
2.6.18-92 kernel.

In Toronto, they are using RHEL 4 U6 to export to RHEL 5.2 and do not=20
have the problem. I am going to downgrade one of my systems here and run =

a test. with RHEL 4 as the server and RHEL 5.2 as the client.

--=20
Jerry Feldman <gaf-mNDKBlG2WHs at public.gmane.org>
Boston Linux and Unix
PGP key id: 537C5846
PGP Key fingerprint: 3D1B 8377 A3C0 A5F2 ECBB  CA3B 4607 4319 537C 5846