NFS 4 client callback port

[Guillaume Rousse]

Talpey, Thomas a écrit :
> At 03:52 AM 6/12/2008, Guillaume Rousse wrote:
>> J. Bruce Fields a écrit :
>>> Argh--my apologies.  I totally forgot about
>>> /proc/sys/fs/nfs/nfs_callback_tcpport.  I believe that should let you
>>> set the client's callback port to the port of your choosing.
>> Cool :)
>>
>> This setting exist both on client and server side, and its default value 
>> is 0. I guess this means 'undefined', and I have to set it on server. 
>> Unfortunatly, most of our nfs4 servers are actually netapp filer, I 
>> don't think they support such setting.
> 
> Guillaume - in NFSv4, the client chooses the callback port, listens on it,
> and passes that number to the server. The server has no choice in the
> matter, and there's no such option on the filer accordingly. If you see
> the setting on your Linux NFS server, that's actually for its client NFS
> module, which you aren't using.
Cool, I'll try this.

>> And while on the topic, we do have lots of similar listening connections 
>> on our clients, even those without any network filtering from the server:
>> tcp        0      0 *:48826                     *:* 
>>     LISTEN      -
>> tcp        0      0 *:45338                     *:* 
>>     LISTEN      -
>> tcp        0      0 *:39482                     *:* 
>>     LISTEN      -
>>
>> I guess they are related to delegation recalling, but is this normal 
>> they are so many of them (around 100) ? And the fact than no related 
>> process is displayed is quite frightening at first :) Would it be 
>> possible to display kernel process here, as in ps output (but maybe it 
>> is a netstat issue there) ?
> 
> You can see the owning process with the netstat "-p" option. Please
> check - I'd be surprised if the client is creating such a large number of
> listening callback ports. Sounds like a bug, if so. How many mounts?
I did use netstat -p option...

First host, 4 mount points, 111 listening connections (it was 100 this 
morning)

Second host, 5 mount points, 84 listening connections (it was 80 this 
morning).

We don't have static mount points, we use autofs for everything, I'm 
couting the potential maximum number of simultaneous mount points.

Current filtering rule for the first host is to allow connection from 
the server to the client for packet with source port < 1024 and 
destination port > 32500. There isn't any filtering for the second host.

-- 
Guillaume Rousse
Moyens Informatiques - INRIA Futurs
Tel: 01 69 35 69 62