create database/disk init

Hi experts,

I have a question regarding creation of a new data base in ASE Server 15.5

Should i first create the disk allocation fand then launch

-create database on xxxx.dat

or the command

-create database creates automatically the disk allocation?

I mean:

First option:

disk init

name = "user_disk",

physname = "/usr/u/sybase/data/userfile1.dat",

size = 5120,

Create database myDB

on "user_disk" ='size'

log on "user_disk"='size

Second option execute only create database without disk init:

Create database myDB

on "user_disk" ='size'

log on "user_disk"='size

Thank you