While installation solaris we get 512 MB swap space default.

Virtual Swap Space  it is a combination of swap areas i.e  partitions and/or  files + Free physical Memory

swaps unused pages on memory in and out of the swap areas.

#swap -l                     //  Gives device and/or files  information configured for swap
                                     Shows us the total swap blocks and free space. 
                                     Does not take physical memory into account.
      

#swap -s                //Lists swap space, including physical memory  


Swap File Creation.

#mkfile    : Creates 0 filled swap file.
#swap -a   : activates the swap file.

#mkfile 1024m /data/swapfile
#swap -a /data/swapfile            

To remover swap file
#swap -d /data/swapfile
#rm -rf /data/swapfile

To create a partion for swap

create a slice.
Then execute below to activate particular slice/partition for swap
#swap -a /dev/c0t1d0s2


To add entry in /etc/vfstab
/data/swap         - - swap - no -  # For swap files
/dev/dsk/c0t1d0s1       - - swap - no -  # For partition