[CentOS] mounting a CentOS 5.5-based NFS partitions from a Mac OS X machine

Tom H tomh0665 at gmail.com
Wed Jul 6 15:57:35 UTC 2011

On Wed, Jul 6, 2011 at 6:54 AM, Louis Lagendijk
<louis at lagendijk.xs4all.nl> wrote:
> On Tue, 2011-07-05 at 22:13 -0400, Tom H wrote:
>> On Tue, Jul 5, 2011 at 1:11 PM, Rob Kampen <rkampen at kampensonline.com> wrote:
>> > Boris Epstein wrote:
>> >>>
>> >>> Is the OS X firewall blocking nfs?
>> >>>
>> >>> How are you mounting the export? If you're not trying it from within
>> >>> Terminal, does it work from within it?
>> >>
>> >> The OS X firewall dos not appear to be a factor. Actually it works
>> >> just fine when I turn off the firewall on the CentOS end.
>> >>
>> >> Could it be that even when I am trying to mount over the TCP the NFS
>> >> client on the Mac OS X side still tried to connect to some UDP port? I
>> >> am asking that because everyone else mounts just fine with the
>> >> firewall up on the server end.
>> >
>> > As I recall OS X only does NFS via TCP - other clients can use UDP - make
>> > sure your CentOS firewall has the TCP ports open.
>> OS X does use TCP but I've just run tcpdump on an F15 VM while
>> mounting and unmounting an NFS share from my Mac. Both the mount and
>> umount result in four UDP packets, two to the portmapper and two to
>> random ports.
>> I don't have time to experiment further right now but perhaps opening
>> up 111 UDP will allow your Macs to mount the NFS shares.
> NFSv3 uses the nfs port (TCP or UDP), portmapper (UDP) and some random
> UDP ports for quota, lockd, mount, and statd. These random ports can be
> fixed by setting them in /etc/sysconfig/nfs. They are normally commented
> out, but uncommenting them (and setting them to different values if so
> required) will fix them so you can firewall them.

Thanks doe the reminder! :)

My mind's been corrupted by recent Linux releases; I assumed that OS X
defaulted to nfsv4 and tcp and my mind didn't connect the random ports
with the pre-nfsv4 nfs elements (probably also because I always make
them static!).

It does default to tcp but doesn't default to nfsv4.

Specifying "-o tcp" produces the udp packets as not specifying "-o
tcp" so OS X's trying tcp and then falls back to udp.

Specifying "-o vers=4.0alpha" produces no udp packets. Perhaps the
version of OS X being released this summer'll have a non-alpha nfsv4

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