As long as your assigned swap is equal or more than your physical RAM, its safe..
I cant assist you without much info..
1.Use mkfile to create a file suitable for a local swap area. For example, to create a 1GB swap file:
/usr/sbin/mkfile 1024m /swapwhere /swap is the name of the file to be used as swap space. Units for the size can be kilobytes (k), blocks (b), or megabytes (m).
2.Tell the system to start using the file as swap:
/usr/sbin/swap -a /swapUse
swap -l to verify that the swap file has been activated.
Put an entry in /etc/vfstab also.
for your reading
BigAdmin Submitted Article: Impact of Swap Space on System Performance for the Solaris 9 and 10 OS