> We are running listserv 15.5 on AIX on a machine with lots of disk and
> memory.  Server often crashes when the lists are searched.

Increase memory quotas, including any kernel parameters or swap space increases that may be necessary to make that increase actually happen :-) I am not aware of any known crashes with large indexes that are not related to hitting a process quota, and I run lists that have been around up to 22 years ;-)

  Eric