Onunload/Onload

I am setting up a second Informix (7.24.UC5/Solaris 2.6) instance on the same box as an instance that is already running and can be shut down only on a temporary basis. Although I am only transporting one database to the new instance, it is the biggest part of its 86 gig instance. The database has some 1,400 tables, the largest of which is 50,000,000 rows, and I do not have large amounts of disk space available. I do have at my disposal, however, a single DLT 4000 20 gig tape unit. Taking into account all the Informix data migration tools available, I have decided to use onunload/onload, especially since I am trying to minimize operator/programmer intervention. However, I keep getting an error 4 after about 4 hours of unloading (UNIX translation: "Interrupted System Call" ? ) Does anyone have any experience with this tool? What gives? Is onunload not "smart" enough to sense EOT and ask for another tape? And will have the same trouble loading (assuming I can ever get this beast unloaded)? Is there a better way to do this? Any guidance anyone can give would certainly be appreciated. TIA, Milton J. Vidrine, Jr.