Hi, try setting the file synchronization mode to per write:
<property name="location" value="/pathToStore"/>
<property name="fsyncMode" value="perWrite"/>
This did not help. Still I am getting "too many open files" after setting this and a restart.
We're experimenting with a file cache store that uses less files, but in the mean time I'd suggest using another cache store, i.e. JDBM, Berkeley, JDBC cache store, Cassandra.