KVM21: Changing VM Parameters

# In The Name Of Allah .
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# Thu Nov 19 14:20:52 2020
# Written By : zer0err0r .
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# 21, Changing VMs Basic Parameters .

  # To change vCPUs :
    $ virsh shutdown centos1
    $ virsh edit centos1
      <vcpu>2</vcpu>
    $ virsh create /etc/libvirt/qemu/centos1.xml

  
  # To change RAM :

    # Reducing [1GB to 512MB] :
      $ virsh dominfo centos1 | grep memory
        Max memory:   1048576kb         # 1GB .
        Used memory:  1048576kb         # 1GB .
      $ virsh setmem centos1 524288     # [512mb x 1024 = 524288kb] .

    # Increasing [512MB to 1GB] :
      $ virsh shutdown centos1
      $ virsh edit centos1
        <memory>1048576</memory>        # Leave the <CurrentMemory> as it is .
      $ virsh start centos1
      $ virsh dominfo centos1 | grep memory
        Max memory:   1048576kb         # 1GB .
        Used memory:  524288kb          # 512MB .
      $ virsh setmem centos1 1048576


  # As you see :
    = Because of we needed to modify the VM [.xml] file, We shutted the VM down .
    = Unlike when we reduced the VM RAM size, We did it dynamically without shutting it down .

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# Peace Be Up0n Muhammed .