MMapFile: File locking failed with error code 37

[gaf-mNDKBlG2WHs at public.gmane.org (Jerry Feldman)]

On 01/26/2009 11:12 AM, Jerry Feldman wrote:
> We are having some issues with RHEL 5.2 NFS.  If I run the program on=20
> a system with local disks, everything works fine, but if I run it on=20
> an NFS mounted drive, I get this error. I've tried this on a couple of =

> different systems in my office, on a couple of different directories=20
> including my home directory. I have no problem creating files on any=20
> of the systems. This problem did not show up when we were running RHEL =

> 4 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=20
> 32-bit kernel where the execution environment is RHEL 5.2  x86_64 with =

> a 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=20
> run a test. with RHEL 4 as the server and RHEL 5.2 as the client.
>
I have a Fedora 9 IA64 system and I exported a directory and received=20
this message, somewhat the same, but different errno:
mmap file locking error: Input/output error
MMapFile: File locking failed with error code 5
MMapFile: '/Fubar/from07.dat.0' has been locked by another process.
MMap file creation failed for file /Fubar/from07.dat.0


It would stand to reason that I would have the same error using a Fedora =

9 server since the error is on the server side. AFAIK, this error has=20
been reported, but not fixed. The reason I used an IA64 system is that I =

have 2 idle IA64 servers that I can use as NFS servers. Since I know=20
that RHEL 4 U 6 works as an NFS server, I can fire up the 2 IA64 servers =

and between the 2 of them migrate the directories. Mainly, we have just=20
under 1 TB of storage. On the current server I have 10 slots with 2=20
300GB SCSIs + a few more 72GB. The IA64 systems have 2 and 3 slots. I=20
can free up a 300G drive on our backup server to start the migration,=20
and try to free up anothger 300GB drive. I'm trying to do this for zero=20
cost. Certainly the best solution is to get a fix for the 2.6.18 kernel=20
on RHEL 5.2 because all my X86_64 systems need to be RHEL 5.2 because=20
the current releases of our products won't run on RHEL 4. We've asked=20
the IT people to give us the user name and password so we can log in to=20
Red Hat and place a bug report.



--=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