How do I verify that an nfs connection is established and is "passing
traffic". I tried netstat -a and I believe I got something....

In jumpstarting a client, from the jumpstart server, on the jumpstart
server I see..
netstat -a
JUMPSTART-SERVER.nfsd          CLIENT.printer         42408      0
49232      0 ESTABLISHED

What is the "printer" appended to name of the client? Is the printer
port being used?(this was during a jumpstart)....

Is there any command that will, very verbosely, show the nfs
connection between client and server?

Kartik Vashishta

On Jun 2, 4:47=A0pm, p...@kartik.com wrote:
> How do I verify that an nfs connection is established and is "passing
> traffic". I tried netstat -a and I believe I got something....
>
> In jumpstarting a client, from the jumpstart server, on the jumpstart
> server I see..
> netstat -a
> JUMPSTART-SERVER.nfsd =A0 =A0 =A0 =A0 =A0CLIENT.printer =A0 =A0 =A0 =A0 4=
2408 =A0 =A0 =A00
> 49232 =A0 =A0 =A00 ESTABLISHED
>
> What is the "printer" appended to name of the client? Is the printer
> port being used?(this was during a jumpstart)....
>
> Is there any command that will, very verbosely, show the nfs
> connection between client and server?
>
> Kartik Vashishta

snoop maybe ?

pref@kartik.com wrote:
> How do I verify that an nfs connection is established and is "passing
> traffic".

From which end are you looking?  Client or server?

> I tried netstat -a and I believe I got something....

Netstat -a is only going to show TCP connections (there's no such thing
as a UDP connection).  So you might see a TCP connection, but that's not
required for NFS.

> In jumpstarting a client, from the jumpstart server, on the jumpstart
> server I see..
> netstat -a
> JUMPSTART-SERVER.nfsd          CLIENT.printer         42408      0
> 49232      0 ESTABLISHED
> 
> What is the "printer" appended to name of the client? Is the printer
> port being used?(this was during a jumpstart)....

Maybe, but that doesn't mean anything.  The client port isn't specific.
It picked one, and snoop decoded that port to be the printer port.  But
that doesn't matter.

> Is there any command that will, very verbosely, show the nfs
> connection between client and server?

No, because NFS doesn't have "connections" in the traditional sense.
It's stateless for the most part. 

You can ask if someone has mounted the filesystem and has not unmounted
it with 'showmount -a'.  But that information can be incorrect.  If a
client crashes rather than cleanly unmounts, stale information can be
left there. 

Seeing a TCP connection on the nfsd port is a pretty good indication
though.  It just isn't required to be there.

-- 
Darren

Hi,

some mistakes...


Darren Dunham wrote at 02.06.2009 18:15
> Netstat -a is only going to show TCP connections (there's no such thing
> as a UDP connection).  So you might see a TCP connection, but that's not
> required for NFS.

wrong for Solaris 10. With NFSv4 NFS became stateful and always use TCP.


>> In jumpstarting a client, from the jumpstart server, on the jumpstart
>> server I see..
>> netstat -a
>> JUMPSTART-SERVER.nfsd          CLIENT.printer         42408      0
>> 49232      0 ESTABLISHED
>>
>> What is the "printer" appended to name of the client? Is the printer
>> port being used?(this was during a jumpstart)....


use netstat -an instead. Port 2049 now is fix for NFSv4. Client port 
number is random.


  > No, because NFS doesn't have "connections" in the traditional sense.
> It's stateless for the most part. 

This is true for NFS Versions 2&3, but default version in solaris 10 is 
NFSv4

> You can ask if someone has mounted the filesystem and has not unmounted
> it with 'showmount -a'.  But that information can be incorrect.  If a
> client crashes rather than cleanly unmounts, stale information can be
> left there. 

That's a problem in solaris 10: you cannot see if a remote machine has 
mounted one of my shared directories. /etc/rmtab is not longer used in 
NFSv4. Actually, the only way is to find used sockets with #netstat -an
or use DTrace to trace mount/unmount operations.

Regards,

Michael




> Seeing a TCP connection on the nfsd port is a pretty good indication
> though.  It just isn't required to be there.
>