topic Re: How to restart NFS server safely in Operating System - HP-UX

How to restart NFS server safely

senthil_kumar_1 — Wed, 09 Dec 2009 12:37:00 GMT

Hi All,

I am using HP-UX 11.11, NFS service are running on that.

Now i want to add some new NFS shares in /etc/exports file. so that i have to restart the NFS service running.

I have some following questions on restarting NFS service:

1)How to view what are the NFS clients are accessing NFS shares available in NFS server?

2)What happen if we are restarting the NFS server while NFS client is accessing some NFS shares?

3)Will the NFS mount points of NFS client automatically connect to NFS server after restarting the NFS server?

4)How to restart the NFS server safely? what are the commands to be used.

Re: How to restart NFS server safely

Michal Kapalka (mikap) — Wed, 09 Dec 2009 12:53:39 GMT

hi,

just add lines ( entries ) to the /etc/exports and use command exportfs -va

the server will automaticaly using new settings without restarting of the NFS server.

on the client side add the entries to the /etc/fstab and mount -a or youst mount it manually.

mikap

Re: How to restart NFS server safely

Michal Kapalka (mikap) — Wed, 09 Dec 2009 12:54:57 GMT

hi,

showmount -e hostname_of_nfs_server

will show you wich FS are exported for which hosts, and which access privileges.

mikap

Re: How to restart NFS server safely

senthil_kumar_1 — Wed, 09 Dec 2009 13:51:04 GMT

1)So if we are using "exportfs -a", the existing NFS mount will not be disconnected? am i correct?

2)But if we are restarting NFS, then all the NFS mounts will be disconnected and connected (after some times) automatically? am i correct?

Re: How to restart NFS server safely

Pete Randall — Wed, 09 Dec 2009 13:54:56 GMT

1) correct

2) sounds more like NFS with automounter - NFS by itself will not mount/dismount automatically.

Pete

Re: How to restart NFS server safely

senthil_kumar_1 — Thu, 10 Dec 2009 13:37:32 GMT

what is the purpose of the service NFSLOCK.

Re: How to restart NFS server safely

Johnson Punniyalingam — Thu, 10 Dec 2009 13:44:10 GMT

It handles file locking for remote and local NFS requests.

Have a look at the rpc.lockd manual page for details

Re: How to restart NFS server safely

Steven E. Protter — Thu, 10 Dec 2009 13:47:27 GMT

Shalom,

NFS Lock handles file locking for NFS. NFS file locking in version three of NFS is not very reliable. NFS version 4, which is only available on 11.31 HP-UX handles file locking efficiently.

sEP

Re: How to restart NFS server safely

Michal Kapalka (mikap) — Thu, 10 Dec 2009 13:49:46 GMT

hi,

check the man page :

http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/V50_HTML/MAN/MAN8/0209____.HTM

mikap

Re: How to restart NFS server safely

Steven Schweda — Thu, 10 Dec 2009 13:59:03 GMT

> check the man page :
> [...]

Who thinks that a "man" page for an obsolete
version of Tru64 is the best source of
information for "HP-UX 11.11"?

Re: How to restart NFS server safely

Michal Kapalka (mikap) — Thu, 10 Dec 2009 14:10:17 GMT

hi Steven,

yes you have right, my misteak,

in the attachment you will find the man page.

sorry for my wrong response.

mikap

Re: How to restart NFS server safely

Viktor Balogh — Thu, 10 Dec 2009 15:15:10 GMT

>1)How to view what are the NFS clients are accessing NFS shares available in NFS server?

you can check it this way:

# showmount -a

>2)What happen if we are restarting the NFS server while NFS client is accessing some NFS shares?

the client will report a stale NFS file handle, and then you must forcibly umount the share, or you should start serving NFS again on the server

Re: How to restart NFS server safely

senthil_kumar_1 — Thu, 10 Dec 2009 17:17:54 GMT

So that other users can not access the same file if one user is accessing, am i correct?

Re: How to restart NFS server safely

Viktor Balogh — Thu, 10 Dec 2009 19:20:15 GMT

>So that other users can not access the same file if one user is accessing, am i correct?

No, this locking is only for writing. Concurrent acces is permitted, but only one can write to the file at once. Before every write this logfile will be stat'ed, if it fails then it cannot be written to the file.

Re: How to restart NFS server safely

Viktor Balogh — Thu, 10 Dec 2009 19:20:56 GMT

s/logfile/loCKfile/

Re: How to restart NFS server safely

senthil_kumar_1 — Mon, 14 Dec 2009 13:38:56 GMT

Hi All,

I have configured NFS server in HP-UX 11.31.

I have done following steps:

1)Created NFS share entry in /etc/exports on sys1 (host name of NFS server):

# vi /etc/exports

/var -root=sys3:sys2

2)Restarted NFS services needed for NFS server:

# /sbin/init.d/nfs.core start
Starting NFS CORE networking

Starting up the rpcbind
/usr/sbin/rpcbind

# /sbin/init.d/lockmgr start
Starting up the Status Monitor daemon
rpc.statd already started, using pid: 987
Starting up the lock manager daemon
/usr/sbin/rpc.lockd

# /sbin/init.d/nfs.server start
Starting NFS SERVER subsystem

Reading in /etc/dfs/dfstab
Starting up the mount daemon
/usr/sbin/rpc.mountd
Starting up the NFS server daemon
/usr/sbin/nfsd
Starting up nfsmapid daemon
/usr/sbin/nfsmapid

3)Now i have executed the below command to view the NFS shares in NFS server (sys1):

# showmount -e
no exported file systems for emdlaghpvm05

# showmount -a

4)Then i executed the below command since the NFS shares are not shown by "showmount -e":

# exportfs -va
shareall -F nfs

5)I am getting below mentioned error while mounting NFS share from NFS client (sys3):

# mount -F nfs sys1:/var /nfs
nfs mount: sys1:/var: Permission denied

How to solve this issue.

Re: How to restart NFS server safely

sujit kumar singh — Mon, 14 Dec 2009 14:39:18 GMT

Hi Senthil

As this is 11.31 you need to use the /etc/dfs/dfstab insted of /etc/exports

add the entries in the /etc/dfs/dfstab as follows:

share -F nfs /var -o root=sys1:sys2
save and exit

exportfs -au
exportfs -a

make sure that on the nfs server as well as the nfs clients the /etc/hosts have the each others entries.

if you /etc/exports there and want to convert the saem to the /etc/dfs/dfstab format, just run the commands as

exportfs -au
exp2dfs
exportfs -a
showmount -e

make sure the nfs server and the nfs clients have each others entries in the /etc/hosts file.

regards
sujit

Re: How to restart NFS server safely

sujit kumar singh — Mon, 14 Dec 2009 14:39:58 GMT

Hi Senthil

As this is 11.31 you need to use the /etc/dfs/dfstab insted of /etc/exports

add the entries in the /etc/dfs/dfstab as follows:

share -F nfs /var -o root=sys1:sys2
save and exit

exportfs -au
exportfs -a

make sure that on the nfs server as well as the nfs clients the /etc/hosts have the each others entries.

if you /etc/exports there and want to convert the saem to the /etc/dfs/dfstab format, just run the commands as

exportfs -au
exp2dfs -- this shall convert the /etc/export entries to /etc/dfs/dfstab entries.
exportfs -a
showmount -e

make sure the nfs server and the nfs clients have each others entries in the /etc/hosts file.

regards
sujit

Re: How to restart NFS server safely

Steven E. Protter — Mon, 14 Dec 2009 15:21:06 GMT

Shalom,

showmount -e localhost

To see after all these changes you have made have altered your NFS shares.

SEP

Re: How to restart NFS server safely

senthil_kumar_1 — Mon, 14 Dec 2009 15:53:21 GMT

So both "/etc/exports" and "/etc/dfs/dfstab" are differing lot in configuration method.

What about the options like root, rw, ro, anon, aync.

Could you please explain about what those options are meaning in /etc/dfs/dfstab.