1. you have to do imanually
2. click on datacenter -> storage, add -> iscsci, add iscsi drive (after this there will be new disk node where VM disk contains CH 00 ID 0 LUN 0)
3. prepare disk (/dev/sdc is our drive) and convert it to GPT

4. fdisk /dev/sdc

5. create partition

6. cfdisk /dev/sdc
   

7. format partition to ext4

8. mkfs.ext4 /dev/sdc1

9. create directory 

10. mkdir /backups
    

11. mount diskt to directory

12. mount -t ext4 /dev/sdc1 /backups

In most cases is enough.