array on sun workstastions

[David Handeli]

 In writing a C program for my Sun 3/60
I seemed to get into some memory difficulties
if global arrays are very large. Though I was well
within memory size of my machine (and Unix uses virtual
arrays anyway) I don't understand how this can occur.
Does anybody have any information on how much global array
size you can have, why indeed there appears to be a limit anyway
on a virtual memory machine?