create ZFS after PVE installation

[alex.tls]

I install PVE on single SSD disk. then I create ZFS with

zpool create  vmpool /dev/sdb /dev/sdc ... /dev/sdf

So I get a pool now, I want to put ISO files and tools as well as run VM within this pool.

1. Do I need to create a dataset before I use that pool? I click on the new storage vmpool(pve), I found I can't find a place to let me update ISO files into this pool, but I can upload ISO file when I click on the storage of local(pve) , as it has a portal call ISO Images.

2. Then I create a few datasets as bellow:

NAME          USED  AVAIL     REFER  MOUNTPOINT
vmpool       2.68M  3.52T      302K  /vmpool
vmpool/iso    279K  3.52T      279K  /vmpool/iso
vmpool/tool   279K  3.52T      279K  /vmpool/tool
vmpool/vm    279K  3.52T      279K  /vmpool/vm

But how can I use those pool? like put ISO files in /vmpool/iso , and put vm disk into /vmpool/vm.

3. Then I check a conf according to this document -- https://pve.proxmox.com/wiki/Storage

root@pve:/etc/pve# cat storage.cfg
dir: local
        path /var/lib/vz
        content backup,vztmpl,iso

dir: tool              ---  so I need to define a new dir type storage  and put newly created dataset here ?
        path /vmpool/tool
        content backup,vztmpl,iso
...

zfspool: vmpool
        pool vmpool
        content images,rootdir
        mountpoint /vmpool
        nodes pve

zfspool: vm      --- so I need to define a new zfspool type storage and put newly created dataset here ?
        pool vmpool
        content images,rootdir
        mountpoint /vmpool/vm
        nodes pve

4. how to make it takes effect immediately without reboot after I have modify storage.cfg.

5. Can I take snapshot for my VM on my /vmpool/vm dataset , do I need to set some properties via zfs set xxx ?

6. Can I take a backup for my VM on my /vmpool/vm dataset , do I need to set some properties via zfs set xxx ?

Anyone can help ?