topic Re: Determining NFS client mounts from the VMS Server in Operating System - OpenVMS

Determining NFS client mounts from the VMS Server

Brian Reiter — Tue, 18 Jul 2006 02:36:35 GMT

Hi Folks,

From OpenVMS (NFS Server) is there a way of determining which clients have NFS mounts active? I could in principal skim through the operator.log file and pick up the mount/dismount requests, just wondering if there is another way.

We're using TCPIP 5.4 ECO 5

Regards, and thanks for your help.

Brian

Re: Determining NFS client mounts from the VMS Server

Wim Van den Wyngaert — Tue, 18 Jul 2006 03:27:40 GMT

UCX sho servi nfs/fu
-> protocol used is UDP per default.

UDP is stateless. There is no connection active for mounted shares.

Never tried NFS in TCP mode yet.

Wim

Re: Determining NFS client mounts from the VMS Server

Wim Van den Wyngaert — Tue, 18 Jul 2006 04:19:38 GMT

A list of clients that have mounted the share can normally be found in rmtab on Unix.

In my log file of NFS mountd I found messages "cannot dump mountlist to tcpip$etc:mountdtab.dat". May be that's the undocumented alternative of rmtab ?

Is "ucx show mount/all" showing anything ?

I created it as a flat file : no improvements. Boot server. Idem. Google didn't find any doc.

Wim

Re: Determining NFS client mounts from the VMS Server

Brian Reiter — Tue, 18 Jul 2006 05:05:30 GMT

From the VMS clients the TCPIP SHO MOUNT works fine, however there could be a number of architectures (Windoze,Unix,Linux and VMS) participating as NFS clients and it would be good to grab all the info from the server side (no need then to worry about different RSH scripts depending on client type).

TCPIP SHO NFS gives come clues as to what's going on but doesn't show the current mounts.

Re: Determining NFS client mounts from the VMS Server

Volker Halle — Tue, 18 Jul 2006 05:06:07 GMT

Brian,

I'm running TCPIP V5.5:

SYS$SPECIFIC:[TCPIP$ETC]MOUNTDTAB.DAT

seems to contain the desired data, but it's accessed by TCPIP$MOUNTD_1 exclusively, so it's quite hard to get to it's contents. I found the file header in INDEXF.SYS, obtained the LBN and used the DISKBLOCK (OpenVMS Freeware) utility to read and dump the contents of the file.

It seems to contain information like this:

remote_node:/local_file_system

If the local file system has been dismounted by the remote NFS client, the first character of the remote_node name seems to be replaced by '#'.

Volker.

Re: Determining NFS client mounts from the VMS Server

Brian Reiter — Tue, 18 Jul 2006 05:26:53 GMT

Now thats handy, just did a BACKUP/IGNORE=INTERLOCK to see what was in it. Definitly looks like the kind of thing I need. Don't need to do it very often, a snapshot every couple of hours should suffice for my purpose.

Many thanks

Brian

Re: Determining NFS client mounts from the VMS Server

Wim Van den Wyngaert — Tue, 18 Jul 2006 05:57:37 GMT

Wonder what it does when a node crashes and stays down. To my knowledge there is no keepalive in NFS and thus the entry will stay in the list.

Volker : what is the char of the file ? I created it empty but still get invalid device in the log file (or is there a logical ? The error message gives the full name.)

Wim

Re: Determining NFS client mounts from the VMS Server

Wim Van den Wyngaert — Tue, 18 Jul 2006 05:58:33 GMT

BTW : anyone with 5.3 eco 2 who has the file ?

Wim

Re: Determining NFS client mounts from the VMS Server

Brian Reiter — Tue, 18 Jul 2006 06:03:03 GMT

FWIW, it looks like a TCPIP DISM/ALL isn't reflected by the server, nor does it seem that old entries are removed after a client restart.

Still better than nothing though.

Re: Determining NFS client mounts from the VMS Server

Wim Van den Wyngaert — Tue, 18 Jul 2006 06:14:48 GMT

Just "stripped" the mountd exe. No logical for the file. And the file is gone after a reboot.

Wim

Re: Determining NFS client mounts from the VMS Server

Wim Van den Wyngaert — Tue, 18 Jul 2006 06:16:28 GMT

http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/V50_HTML/MAN/MAN4/0170____.HTM

explains some things.

Wim

Re: Determining NFS client mounts from the VMS Server

Volker Halle — Wed, 19 Jul 2006 00:35:20 GMT

Wim,

in TCPIP V5.5, this file is accessed via TCPIP$ETC:MOUNTDTAB.DAT - a sequential STREAM_LF file.

In this version of TCPIP a TCPIP DISM from a client seems to be reflected in that file by replacing the first character of the remote:/local_file_system entry with a '#' character. Certainly only an explicit TCPIP DISM will cause the entry to be 'invalidated'. The mountdtab man page link provided above explains this as well.

As this file does not seem to be mentioned in the TCPIP documentation, usage of this file is probably considered unsupported.

Volker.

Re: Determining NFS client mounts from the VMS Server

Brian Reiter — Thu, 20 Jul 2006 04:03:19 GMT

Got some form of workaround now.

Many thanks

Brian