can you (theoretically) run only NFSv4 (without earlier versions)?

Robert P. J. Day rpjday at crashcourse.ca
Tue Dec 24 01:12:20 UTC 2013


Quoting Ed Greshko <Ed.Greshko at greshko.com>:

> On 12/24/13 08:15, Robert P. J. Day wrote:
>> Quoting Ed Greshko <Ed.Greshko at greshko.com>:
>>
>>> On 12/24/13 07:16, Robert P. J. Day wrote:
>>>> Quoting Tom H <tomh0665 at gmail.com>:
>>>>
>>>>> On Fri, Dec 20, 2013 at 2:34 PM, Robert P. J. Day  
>>>>> <rpjday at crashcourse.ca> wrote:
>>>>>>
>>>>>> a long, long time ago, i reported an apparent glitch with NFS on
>>>>>> fedora:
>>>>>>
>>>>>> https://lists.fedoraproject.org/pipermail/users/2010-January/097465.html
>>>>>>
>>>>>> in that, at the time, it *appeared* that you couldn't set up
>>>>>> NFS so that *only* version 4 was running. before i start messing
>>>>>> with this again, anyone know whether that's changed? that is,
>>>>>> is it possible to set up a network in which only NFSv4 is running,
>>>>>> and no earlier versions are supported? thanks.
>>>>>
>>>>> It's been possible to run nfsv4-only nfs for a long time, with only
>>>>> port 2049 being let through the firewall. It only appears that you
>>>>> can't because because rpc.mountd has to run on the server but it's
>>>>> only involved in the exporting and not the mounting.
>>>>
>>>>   how does one configure fedora 20 to support only NFSv4? i'm used to
>>>> mucking with /etc/sysconfig/nfs in earlier versions of RH, and tweaking
>>>> the variables MOUNTD_NFS_V* and RPCNFSDARGS. i don't see those vars
>>>> in fedora 20 and, according to "rpcinfo -p", i'm currently supporting
>>>> NFS versions both 3 and 4. so how does one turn off NFSv3? thanks.
>>>>
>>>>
>>>
>>> In /etc/sysconfig/nfs
>>>
>>> # Optional arguments passed to rpc.nfsd. See rpc.nfsd(8)
>>> RPCNFSDARGS=""
>>>
>>> man 8 rpc.nfsd
>>>
>>>       -N  or  --no-nfs-version vers
>>>               This option can be used to request that rpc.nfsd  
>>> does  not  offer
>>>               certain versions of NFS. The current version of  
>>> rpc.nfsd can sup‐
>>>               port NFS versions 2,3,4 and the newer version 4.1.
>>>
>>> Would seem to be what you are searching.
>>
>>   i tried that and it didn't seem to work, in the sense that when i
>> ran "rpcinfo -p" to verify the result, here's part of the output:
>>
>>     100003    3   tcp   2049  nfs
>>     100227    3   tcp   2049  nfs_acl
>>     100003    3   udp   2049  nfs
>>     100227    3   udp   2049  nfs_acl
>>     100003    4   tcp   2049  nfs
>>     100003    4   udp   2049  nfs
>>
>> so isn't that telling me i still have both versions 3 and 4? here's
>> the line i added to the file:
>>
>> RPCNFSDARGS="-N 2 -N 3"
>>
>
> Port 2049 is used by V4.  I don't think V3 or V2 uses it....
>
> I would add to the parameters -U to disable UDP and then attempt a  
> mount while specifying that nfs version 3 be used.  That will verify  
> it.

   as a quick test, i added "-U" but the only change was that
"rpcinfo -p" showed me that UDP was no longer being accepted
for v4 only:

     100003    3   tcp   2049  nfs
     100227    3   tcp   2049  nfs_acl
     100003    3   udp   2049  nfs
     100227    3   udp   2049  nfs_acl
     100003    4   tcp   2049  nfs

to match what i see under RHEL, i was hoping to see *all*
references to NFSv3 disappear from the output of that command.
i'll test further later.

rday



More information about the users mailing list