mountd Invalid radix node head (9-STABLE)

[Alban Hertroys]

On 13 Jan 2014, at 1:06, Rick Macklem <rmacklem at uoguelph.ca> wrote:

> Alban Hertroys wrote:
>> I’ve been messing around with my NFS exports definitions to add some
>> new mount-points to the list and I got most of it working again (at
>> least, the important bits).
>> 
>> However, 2 exports in that file are causing problems. When I restart
>> mountd, they log lines like:
>> 
>> Jan 12 16:01:14 solfertje mountd[99349]: can't change attributes for
>> /usr/home/smb: Invalid radix node head, rn: 0 0xfffffe0023e1c600
>> Jan 12 16:01:14 solfertje mountd[99349]: bad exports list line
>> /usr/home/smb     -mapall
>> Jan 12 16:01:14 solfertje mountd[99349]: can't change attributes for
>> /usr/home/vhosts/django: Invalid radix node head, rn: 0
>> 0xfffffe0023e1c600
>> Jan 12 16:01:14 solfertje mountd[99349]: bad exports list line
>> /usr/home/vhosts/django     -mapall
>> 
>> What does that message mean? Where do I look to fix this?
>> 
> Are these paths (/usr/home/smb and /usr/home/vhosts/django) separate file
> systems on the server from the others?
> 
> If they are on the same server file system as one of the other entries,
> then the paths need to be added to that entry. You cannot have multiple
> entries for the same server file system and exported host/subnet.

Ah, you’re right! Makes sense now, thanks.

Still, that error message I got seems rather peculiar; is that supposed to happen if you mix directories and mount points like that?

I think I got thrown off by the bad exports line errors that the new directories I added were causing originally, but those new entries were file-system mount points while the original entries weren’t. And you can’t mix those, as you say.
I even read the section of the man page about that, but that bit didn’t register.

I find that man-page to be a bit unclear frankly.

1). From a configuration point of view it doesn’t seem to make a whole lot of sense to separate plain directories from file-system mount points, why the distinction? Is it really necessary? I think if exports wouldn’t make that distinction, it would save head-aches for a lot of users who mix the two without realising.

2). The distinction between directories and mount points doesn’t get any clearer with the addition of the NFSv4 tree root syntax that (by its syntax) suggests that a whole file-system (the tree root) will be exported - which is often very much not what you want. There is mention that that’s not the case, but what does that line really do? Why do we need that? It’s not clear from the man page and it sounds like the NFS server should be able to figure the tree root(s) out by itself from the list of directories to export.

3). The text in that man page is rather dense. There’s a lot of “and this and that and so and so” going on, all within the same section that describes the 3 fields in an export line *and* several methods to implement them.
I expect that document would get quite a bit clearer if the various enumerations would be separated, for example by giving the 3 fields a separate paragraph each with (optional) enumerated lists for the various ways those fields can be implemented.

The above points give me the impression that setting up an NFS server (on FreeBSD?) is harder than it needs to be.

That said, try setting up OS X Mavericks as an NFS client! Most of the Google results you get for how to set that up get it “wrong".
For those interested: The “proper approach” (the one the colour of my bikeshed) turns out to use the hidden /System/Library/CoreServices/Directory\ Utility.app to create mount point entries.
It’s described in more detail here: http://mbcdev.com/2012/09/15/adding-nfs-shares-on-os-x-with-directory-utility/

Here’s the kicker though: Mount points are not allowed to mount in the local directory /Volumes, where they used to be created by default in earlier versions of OS X - such definitions will silently fail!

And that’s just the client; I don’t want to find out how to set up an NFS *server* on OS X… Thankfully, that part’s covered by FreeBSD.


Anyway, thanks for the help and I hope my suggestions prove useful to someone.

Alban Hertroys
--
If you can't see the forest for the trees,
cut the trees and you'll find there is no forest.