NFS acting weird?

[Tom Horsley]

I've got filesystems hosted on centos 7. They are mounted
(nfs4) on my newly configured fedora 29 desktop.

I'm debugging an executable that lives on the NFS filesystem.
I make changes and recompile over on the centos system.

I try testing the newly compiled executable on fedora 29
and it acts totally strange in ways that make no sense.

I reboot the fedora 29 system and try testing again, and
everything seems to be as expected.

I can't put my finger on anything specific, but it sure seems
like NFS is at fault somehow.

When I had fedora 28 on this same desktop and was doing the
same kind of development, the strangeness never manifested.

[Rick Stevens]

On 11/6/18 6:57 AM, Tom Horsley wrote:
>  I've got filesystems hosted on centos 7. They are mounted
>  (nfs4) on my newly configured fedora 29 desktop.
>  
>  I'm debugging an executable that lives on the NFS filesystem.
>  I make changes and recompile over on the centos system.
>  
>  I try testing the newly compiled executable on fedora 29
>  and it acts totally strange in ways that make no sense.
>  
That's singularly useless in letting us help you. Be specific as to
what didn't work.

>  I reboot the fedora 29 system and try testing again, and
>  everything seems to be as expected.
>  
>  I can't put my finger on anything specific, but it sure seems
>  like NFS is at fault somehow.
>  
Try turning off caching on the NFS mount by specifying "noac" in the
options. I don't know if there's a different default for F29 versus F28,
but caching can confuse things. I/O will be slower, but things will be
coherent.
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----------------------------------------------------------------------

[Tom Horsley]

On Tue, 6 Nov 2018 17:46:58 +0000
Rick Stevens wrote:

>  > I try testing the newly compiled executable on fedora 29
>  > and it acts totally strange in ways that make no sense.  
>  
>  That's singularly useless in letting us help you. Be specific as to
>  what didn't work. 
The behavior is singularly random, so it is hard to describe
usefully. It is like the program was designed to compute PI
to 10 digits, but instead it draws a picture of a duck :-).

I'm beginning to suspect that my actual problem is that the
sigsetops routines have changed in the new glibc and I'm getting
random trash in signal sets because I'm getting errors from
things like sigaddset I didn't get with f28 libs and I'm going down
strange and wondrous code paths.

I still have no idea why the behavior always radically changes
when I relink the program on the remote system though.

[Cameron Simpson]

On 06Nov2018 09:57, Tom Horsley <horsley1953(a)gmail.com&gt; wrote:
> I've got filesystems hosted on centos 7. They are mounted
> (nfs4) on my newly configured fedora 29 desktop.
>
> I'm debugging an executable that lives on the NFS filesystem.
> I make changes and recompile over on the centos system.
>
> I try testing the newly compiled executable on fedora 29
> and it acts totally strange in ways that make no sense. 
Compiled on the Centos system, but dynamicly linking to library from the 
Fedora system? That could be a bad combination.

Are the outputs of "ldd your-executable", run on fedora and centos, 
different?

> I reboot the fedora 29 system and try testing again, and
> everything seems to be as expected. 
Weird.

> I can't put my finger on anything specific, but it sure seems
> like NFS is at fault somehow. 
So: copy the source to fedora and compile on fedora. Is the behaviour 
normal or weird?

Guessing in the dark here, but a dynamicly linked executable will be 
getting its library from the local system. But if it was compiled 
remotely the headers will describe the remote system libraries. Binary 
level badness if things mismatch, possibly.

Cheers,
Cameron Simpson <cs(a)cskk.id.au&gt;