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<topic xml:lang="en-us" id="storage-bandwidth-limit">
            <title>Limiting Bandwidth for Disk Images</title>
            
            <body>
               <p><ph conkeyref="vbox-conkeyref-phrases/product-name"/> supports limiting of the maximum bandwidth used
      for asynchronous I/O. Additionally it supports sharing limits through bandwidth groups for several images. It is
      possible to have more than one such limit. </p>
               <p>Limits are configured using <userinput>VBoxManage</userinput>. The example below creates a bandwidth
      group named Limit, sets the limit to 20 MB per second, and assigns the group to the attached disks of the VM: </p>
               <pre xml:space="preserve">VBoxManage bandwidthctl "VM name" add Limit --type disk --limit 20M
VBoxManage storageattach "VM name" --storagectl "SATA" --port 0 --device 0 --type hdd
                                   --medium disk1.vdi --bandwidthgroup Limit
VBoxManage storageattach "VM name" --storagectl "SATA" --port 1 --device 0 --type hdd
                                   --medium disk2.vdi --bandwidthgroup Limit</pre>
               <p>All disks in a group share the bandwidth limit, meaning that in the example above the bandwidth of
      both images combined can never exceed 20 MBps. However, if one disk does not require bandwidth the other can use
      the remaining bandwidth of its group. </p>
               <p>The limits for each group can be changed while the VM is running, with changes being picked up
      immediately. The example below changes the limit for the group created in the example above to 10 MBps: </p>
               <pre xml:space="preserve">VBoxManage bandwidthctl "VM name" set Limit --limit 10M</pre>
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         </topic>
