When using moodle on a clustered system that shares moodledata repositories on an NFS mounted volume, the Global Search indexer cannot run because invoking the system level flock() primitive in Lucene.

flock() is known not running on NFS distributed file systems.

We need a turn around for this, as Global Search becomes really usefull on large scale systems that are likely to use a remote shared filesystem.

Fixing this is somewhat tricky as :

- fixing it from at underlying file system level seems not being affordable
- fixing it at PHP level seems not being affordable either, because would need a php library fix or turnaround.
- fixing it in Lucene seems being the only way to have a turnaround, but this will break the standardization of the distribution.

An advice would be welcome to determine the nicest strategy here.

Thanks.