The issue with NFS and SQLite is that posix advisory locks
do not work, or do not work well, on many NFS installations.
As long as advisory locks work over NFS, or as long as there
is only one client trying to access the database at a time, so
that locks are not really needed, SQLite works fine
over NFS. NFS is a lot slower, but that's just the nature
of NFS and SQLite can't do anything about that.
You can ask SQLite to use dot-file locking instead of posix advisory locking. Or you can ask it to simply ignore locking all together. In both cases, SQLite will work on even a broken NFS system, though with the corresponding concurrency limitations.