13.3. Using Storage Volumes

Procedure 13.11. Creating Storage Volumes with Virtual Machine Manager

1. Open the storage settings

   1. In the Virtual Machine Manager, open the Edit menu and select Connection Details.
   2. Click the Storage tab in the Connection Details window.
      

      Figure 13.11. Storage tab

      The pane on the left of the Connection Details window shows a list of storage pools.

2. Select the storage pool in which you want to create a storage volume

   In the list of storage pools, click the storage pool in which you want to create the storage volume.
   Any storage volumes configured on the selected storage pool appear in the Volumes pane at the bottom of the window.

3. Add a new storage volume

   Click the button above the Volumes list. The Add a Storage Volume dialog appears.
   

   Figure 13.12. Create storage volume

4. Configure the storage volume

   Configure the storage volume with the following parameters:
   • Enter a name for the storage pool in the Name field.
   • Select a format for the storage volume from the Format list.
   • Enter the maximum size for the storage volume in the Max Capacity field.

5. Finish the creation

   Click Finish. The Add a Storage Volume dialog closes, and the storage volume appears in the Volumes list.

Procedure 13.12. Deleting Storage Volumes with Virtual Machine Manager

1. Open the storage settings

   1. In the Virtual Machine Manager, open the Edit menu and select Connection Details.
   2. Click the Storage tab in the Connection Details window.
      

      Figure 13.13. Storage tab

      The pane on the left of the Connection Details window shows a list of storage pools.

2. Select the storage volume you want to delete

   1. In the list of storage pools, click the storage pool from which the storage volume is abstracted.
      A list of storage volumes configured on the selected storage pool appear in the Volumes pane at the bottom of the window.
   2. Select the storage volume you want to delete.

3. Delete the storage volume

   1. Click the button (above the Volumes list). A confirmation dialog appears.
   2. Click Yes. The selected storage volume is deleted.

Procedure 13.13. Attaching SCSI LUN-based storage to a guest

1. Create the device file by writing a <disk> element in a new file, and save this file with an XML extension (in this example, sda.xml):

   # cat sda.xml
   <disk type='volume' device='lun' sgio='unfiltered'>
     <driver name='qemu' type='raw'/>
     <source pool='vhbapool_host3' volume='unit:0:1:0'/>
     <target dev='sda' bus='scsi'/>
     <shareable/>
   </disk>  

2. Associate the device created in sda.xml with your guest virtual machine (Guest1, for example):

   # virsh attach-device --config Guest1 ~/sda.xml

   Note

   Running the virsh attach-device command with the --config option requires a guest reboot to add the device permanently to the guest. Alternatively, the --persistent option can be used instead of --config, which can also be used to hotplug the device to a guest.

Procedure 13.14. Creating a virtual SCSI controller

1. Display the configuration of the guest virtual machine (Guest1) and look for a pre-existing SCSI controller:

   # virsh dumpxml Guest1 | grep controller.*scsi

   If a device controller is present, the command will output one or more lines similar to the following:

   <controller type='scsi' model='virtio-scsi' index='0'/>
   

2. If the previous step did not show a device controller, create the description for one in a new file and add it to the virtual machine, using the following steps:
   1. Create the device controller by writing a <controller> element in a new file and save this file with an XML extension. virtio-scsi-controller.xml, for example.

      <controller type='scsi' model='virtio-scsi'/>
      

   2. Associate the device controller you just created in virtio-scsi-controller.xml with your guest virtual machine (Guest1, for example):

      # virsh attach-device --config Guest1 ~/virtio-scsi-controller.xml

      In this example the --config option behaves the same as it does for disks. See Section 13.3.6, “Adding Storage Devices to Guests” for more information.
3. Add a new SCSI disk or CD-ROM. The new disk can be added using the methods in Section 13.3.6, “Adding Storage Devices to Guests”. In order to create a SCSI disk, specify a target device name that starts with sd.

   Note

   The supported limit for each controller is 1024 virtio-scsi disks, but it is possible that other available resources in the host (such as file descriptors) are exhausted with fewer disks.
   For more information, see the following Red Hat Enterprise Linux 6 whitepaper: The next-generation storage interface for the Red Hat Enterprise Linux Kernel Virtual Machine: virtio-scsi.

   # virsh attach-disk Guest1 /var/lib/libvirt/images/FileName.img sdb --cache none

   Depending on the version of the driver in the guest virtual machine, the new disk may not be detected immediately by a running guest virtual machine. Follow the steps in the Red Hat Enterprise Linux Storage Administration Guide.

Procedure 13.15. Removing storage from a virtual machine with Virtual Machine Manager

1. Open Virtual Machine Manager to the virtual machine hardware details window

   Open virt-manager by executing the virt-manager command as root or opening Applications System Tools Virtual Machine Manager.
   Select the guest virtual machine from which you want to remove a storage device.
   Click Open. The Virtual Machine window opens.
   Click . The hardware details window appears.

2. Remove the storage from the guest virtual machine

   Select the storage device from the list of hardware on the left side of the hardware details pane.
   Click Remove. A confirmation dialog appears.
   Click Yes. The storage is removed from the guest virtual machine.