This global parameter determines if the tdb internals of Samba can depend on mmap working correctly on the running system. Samba requires a coherent mmap/read-write system memory cache. Currently only HPUX does not have such a coherent cache, and so this parameter is set to no by default on HPUX. On all other systems this parameter should be left alone. This parameter is provided to help the Samba developers track down problems with the tdb internal code. Default: use mmap = yes