i have VMware Paravirtual on virtual machine. if i add more cpu or memory. what is mean that Hot add or remove requires a bus rescan from within the guest operating system so i can restart to operation system ?
Depending of your guest OS you can add hot add CPU and memory, but to remove you will need to power off the virtual machine. The following blog post shows a table with all possibilities based on guest OS: vSphere Memory Hot Add/CPU Hot Plug » boche.net – VMware vEvangelist
Hot-add will also need to have been previously enabled via VM settings before this can be used. If you have not already enabled it, you need to shutdown the VM to do so.