Questions about server partition ......

Questions about server partition ...... -- Linux Enterprise Application-Linux server application information. For details, refer to the following section. Prepare a server, plan to use DELL's 2950 (it is said that it is more convenient to install CentOS), the hard disk is directly up to 2 TB (now SATA hard disk is about the price of cabbage), RAID5, only use WEB services (not even FTP ). The hard disk is big, but the partition is worrying. How to make full use of the 2 TB capacity is a problem.

A lot of solutions have been searched on the Internet, but they are all N years ago-those who cherish the gold, and most of the partition solutions are test-type, so I don't feel very practical.
I also checked the file structure of LINUX, but some problems still cannot be solved. Therefore, I would like to ask:

1. is/home necessary for pure WEB Services (without a second virtual host? -- It is generally recommended that the remaining partitions be allocated to the root directory and/home. I don't know what data will be generated under/home, because apart from root, other users cannot log on to the server. Therefore, there is only one root user. during routine maintenance, how much data should be generated?

2. I used PHPnow in the WINDOW to perform experiments. mysql databases are in the mysql folder and html files are in the htdocs folder. Now, in linux, these files are usually stored in the/usr directory. Should I divide the necessary/home space and leave all the remaining files to it?

3. How many partitions are required for other directories, such as/var/tmp?

If you have any experience, please advise or give a suitable partition solution based on the 2 TB capacity. Thank you!