Fedora 9: dbus problems with /home on nfs

[David Jansen]

Thanks for all your input, see comments below

On Mon, Jul 14, 2008 at 04:44:18PM -0400, Todd Denniston wrote:
> I think we kind of lost the OP's problem.
>
> John Austin wrote, On 07/14/2008 03:39 PM:
>> On Mon, 2008-07-14 at 08:06 -0430, Patrick O'Callaghan wrote:
>>> On Mon, 2008-07-14 at 13:07 +0100, Anne Wilson wrote:
>>>> On Monday 14 July 2008 12:47:25 Tom Horsley wrote:
>>>>> On Mon, 14 Jul 2008 11:21:28 +0200
>>>>>
>>>>> David Jansen <jansen at strw.leidenuniv.nl> wrote:
>>>>>> Has anyone else seen this?
> OP summary:[
> /var/log/messages shows
> kernel: dbus-daemon[22141]: segfault at 1c ip
> 7fa454a5f2e0 sp 7fff5ca79fa8 error 6 in dbus-daemon[7fa454a31000+4c000]
> after gdm login of users on NFS.
> ]

Yes, that's a good summary of a bad situation :)

>
>>>>> I have noticed some kind of problem with logging in
>>>>> via GDM when I use a user with an NFS home, but never
>>>>> investigated exactly what the problem was because it
>>>>> is usually only by accident that I try it.
>
> Do you [or the OP] use soft mounts?
> I have seen enormous problems, no matter which OS/version is acting as 
> the server, if the clients are soft mounting home with nfs, and it is 
> worse if the home directories are being automounted.

I didn't use automount for /home, which I want permanently mounted
anyway. But I had the entry in /etc/fstab just withg "defaults" as mount
option. 'man 5 nfs' seems to indicate that 'hard' is the default. 
I'll add hard,intr anyway and see if that solves the problem.

> Could the OP's problem be that some part of gnome/kde/gdm/kdm is 
> attempting to have dbus look at something in the users home dir which is 
> an auto/soft mounted dir and either not finding the file or getting an IO 
> error causes dbus-daemon to seg fault? [if the answer is yes, then we 
> have narrowed down the problem, and an appropriate bug needs to be put in 
> the system about dbus as being a daemon it should never die with 
> segfault.]

I'm starting to suspect the gvfs system, which tries to mount stuff
under $HOME/.gvfs and I don't see this mount showing up for a user with
$HOME on nfs, only for users with local homes. I could understand that
it may not have sufficient permissions to mount something under a remote
nfs mount, but I would expect an error message; the logs don't seem to
indicate any messages about gvfs.

As for all the other comments about nfs problems: probably true, but it
doesn't explain why Fedora <= 8, RHEL, and Solaris all seem to be
perfectly happy with the network and nfs setup. It's certainly a new
problem in fedora 9, or a new feature in Fedora 9 (like gvfs?) triggers
the problem.

Anyway, I have a new set of options to test, to see if that solves
anything. Thanks to everyone who has resonded so far.

David Jansen