The exposure in your scheme is that LISTSERV may need access to the data on the disk. The filemode itself is not an issue for dynamic disks - as long as you relink the disk, LISTSERV will re-access as needed. The dynamic access code was designed to withstand sysprog tampering (as long as it is not done in the middle of a command of course). However, if the disk is not linked when it is needed, LISTSERV gets scared and logs out to avoid losing data. It doesn't know how to relink it, and even if it did it might not be a good idea. Eric