[ome-users] Binary repo on NFS (was: import error)

[Niko Ehrenfeuchter]

On 23.01.2013 22:09, Josh Moore wrote:
>
> On Jan 23, 2013, at 7:42 PM, Damir Sudar wrote:
>
>> Hi Josh,
>
> Hi Damir,
>
> my apologies for letting this slip. Please do try to CC ome-users
> since the rest of the team won't let me forget! :)
>
>> Based on your initial question about what filesystem, I looked a
>> little further and tried to import the same offending file into a
>> different OMERO installation that we set up for testing. This test
>> installation is also on Ubuntu 12.04LTS but uses a xfs Linux
>> filesystem for the omero.data.dir. And that one had no trouble with
>> the offending file. Have you seen others have trouble with using a
>> CIFS filesystem?
>
> NFS & Samba filesystems have all shown problems in some if not most
> cases. The base requirement is that the posix locking semantics are
> guaranteed. A couple other threads on this topic:
>
> *
> http://lists.openmicroscopy.org.uk/pipermail/ome-users/2012-September/003287.html

picking up this thread in regard to the message you're quoting here - 
apparently the launching of "nfslockd" hasn't been integrated into the 
startup scripts yet. Is that correct?

Josh, as you wrote in the pull request it would be very helpful to have 
a test to check locking. This is extremely important for us as we're 
currently forced to have the binary repository on NFS :-(

So the basic questions that currently come to my mind are:

- what specific variant(s) of locking need to be supported (flock(), 
fcntl(), lockf()), do you have any references that I can feed to our 
storage-experts?
- why is locking done, for multi-threading or multi-nodes (or ...)?
- do you expect that running "nfslockd" is sufficient?
- how can we check if it is working correctly?
- is NFSv4 instead of v3 something that could help?

Thanks a lot!
~Niko