Need hints on multiple residency problem

Hi All I am having a problem with making more than one instance resident on a single machine. The operating system is HP-UX 10.20 and Informix 7.23. The total memory space is 1GB. I have 2 instances on the machine one of which uses 302464 kB of Shared memory and the other 310632 kB. They have differnt SERVERNUM values in the onconfig files. However, when I start one up and try to start up the other, it gives me the error "Fatal Error in Shared Memory Creation" and in the message log it says: shmget: [ENOMEM][12]: key 525b4801: out of shared memory, check system SHMALL mt_shm_init: can't create resident segment This happens regardless of which one I bring up first. SHMALL does not seem to be a Unix kernel parameter that I can change. Any pointers or suggestions would be greatly appreciated. TIA Sujit Pal