I assume with server you mean the physical box.
Since you are running on Solaris: No problem!
The most common setup is to install the server into two different Sybase trees. Basically you have a structure like:
/sybase/1151/...
/sybase/1192/...
You just have to make sure to set $SYBASE to the right environment (and possibly you want to adapt $PATH).
Be very careful with a production system though. When you boot the wrong server, pointing to the wrong devices (which is virtually impossible though, if you organize yourself) you might be in big trouble.
On NT it's not quite that simple.
HTH
Alain