topic Re: Rexporting NFS mount in Operating System - HP-UX

Rexporting NFS mount

Ramesh_27 — Fri, 16 Apr 2004 13:57:27 GMT

Hi

I am planning to export /sys file sytem on Server A. Server B will nfs mount that file system as /disk.

Is it possible for me to reexport /disk?
so that server C can nfs mount it as /sys/disk1

any answers highly appreciated!!!

Re: Rexporting NFS mount

A. Clay Stephenson — Fri, 16 Apr 2004 14:05:14 GMT

There is no need to reexport it. Simply create a mountpoint directory on Server C
e.g. mkdir -p /sys/disk1

and then mount -F ServerA:/sys /sys/disk1

Re: Rexporting NFS mount

Steven E. Protter — Fri, 16 Apr 2004 14:05:47 GMT

vi /etc/exports

add the filesystem and any access restrictions

exportfs -av

You'll get good diagnostics in case anything is misconfigured.

SEP

Re: Rexporting NFS mount

Ramesh_27 — Fri, 16 Apr 2004 14:38:53 GMT

Hi

I misstated my question.

Can server B rexport its nfs mounted filesystems so that ican mount that file system from Server C.

Regds
ramesh

Re: Rexporting NFS mount

A. Clay Stephenson — Fri, 16 Apr 2004 14:52:24 GMT

In depends upon the flavor of UNIX but typically you get an error something like "Too many levels of remote in path". This is not something that I would ever depend upon working and moreover it adds more overhead to an already expensive operation. It makes much more sense to avoid the middle server even if it is supported.
This is the kind of task the automounter was madde to handle.

Re: Rexporting NFS mount

SS_6 — Fri, 16 Apr 2004 14:55:55 GMT

I would recommend not to use -a option and use -i it will ignore options from /etc/exports file.
On serverB add the entry into exports file as mentioned by SEP and do
#exportfs -i -o access=serverC /sys
ON serverC
#mkdir /disk1
#mount serverC:/sys /disk1

DO man on exportfs for more details.

Re: Rexporting NFS mount

SS_6 — Fri, 16 Apr 2004 14:57:40 GMT

sorry last line should be
#mount serverB:/sys /disk1

Re: Rexporting NFS mount

Senthil Kumar .A_1 — Sat, 17 Apr 2004 01:24:06 GMT

hello ramesh,

I am stumped by the reply of SS that server C could mount from server B's /disk1 which is the exported fs of server A. It was mentioned in one of HP doc that you can't re-export the nfs mounted file system. Kudos to SS if it were otherwise as he suggested and if working.

But,I strongly advocate against the usage of such an option....on the contrary I agree with clay's statement more than SS because,if u go ahead with SS option then your server C depends on both Server B AND server A.It is higly recommended not to do this.Whereas if u could nfsmount on server C from server A directly then atleast u are safer because it depends only on server A.

regards
Senthil

P.S : "Certain repremansion is blessing in disguise".please listen to clay stevenson in this regard

Re: Rexporting NFS mount

venugopalakrishna.y.r — Sat, 17 Apr 2004 01:59:35 GMT

hello,

you cannot re-export the nfs mount.
modify /etc/exports on NFS server suitably to
give access to ServerC.
eg. /sys access:ServerB,ServerC
and then run #exportfs command to update /etc/xtab.
on the client side, mount the exported filesystem.

Re: Rexporting NFS mount

SS_6 — Sat, 17 Apr 2004 10:21:48 GMT

okay,I misuderstood the question little bit because of two posting of questions and I am also not in favour of reexporting nfs file system and especially when it is easily possible to export the file system from the (one)same serverA to serverC.I also really don't see any logic to rexport any file system from another server. Thanks guys for pointing it out. Have a nice weekend.

Re: Rexporting NFS mount

SS_6 — Sat, 17 Apr 2004 10:57:06 GMT

If you give a closer look to my solution. I have suggested to reexport /sys and NOT /disk1 which is only possible from serverA.