InterSystems IRIS Installation custom layout structure

Hello Respected members,

I am new with InterSystems IRIS , want to setup the environment on RHEL 7.5 with multiple lun layouts (separate LVM for DB , Journal, and WIJ), 

I would like to get some help in setting up the same, as far as I know, the installation will go through on a single directory ( I did not see any option to chose path/directory for DB's or WIJ /journals), hence after installation I would like to move my DB's to separate LVM and WIJ on another LVM set

Please suggest or share the steps for the  same document if any for the same, that will be really helpful, Thanks

Regards

RS