ontape - not enough memory

Hi all, We are having a problem with ontape restore. We have an informix database more than 12 G. This is on a 7.21 and HP-UX 10.50. This is a 6 CPU box with physical memory of over 3 Gigs. We are trying to have a copy of this database on a smaller 2 CPU box with only 1 Gig of Physical memory. This will be a sort of a test system. We did a level 0 archive using ontape from the source system and are trying to do a cold restore on the target system. All ONCONFIG parameters are same on both sides. We are getting the following error within a minute of starting the restore : Restore Failed - Not enough memory. Is this because of having less memory (we have SHMVIRTSIZE of 400 M and 250000 BUFFERS) ? COuld it be due to lack of Swap space ? Any ideas ?? Thanks, Sameer