Is the method of installation of Unix and Linux the same???
You are going to want to specify (in particular) what version of Unix you are talking about.
Linux install requirements vary. Linux can be put on one partition and a swap file activated.
Things I notice about both FreeBSD and Solaris are that they both require
a primary partition, but are able to "slice" that partition into the needed partitions.
You definately want to read and re-read the documentation on the Unix version you want to install.
"The devil is in the details."