The most important factors in determining swap space size are the requirements of the system's software applications. For example, large applications such as computer-aided design simulators, database management products, transaction monitors, and geologic analysis systems can consume as much as 200–1000 MB of swap space.
Consult your application vendors for swap space requirements for their applications.
If you are unable to determine swap space requirements from your application vendors, use the following general guidelines based on your system type to allocate swap space.
On a system with a ZFS root file system, if you attempt to designate a dump device that is too small to hold a system crash system with the dumpadm –d command, you will see a message similar to the following:
dumpadm: dump device /dev/zvol/dsk/rpool/dump is too small to hold a system dump dump size 43467329536 bytes, device size 42949672960 bytes