12.4. LVM-based Storage Pools

Optional: Create new partition for LVM volumes

1. Create a new partition

   Use the fdisk command to create a new disk partition from the command line. The following example creates a new partition that uses the entire disk on the storage device /dev/sdb.

   # fdisk /dev/sdb
   Command (m for help):
   

   Press n for a new partition.
2. Press p for a primary partition.

   Command action
      e   extended
      p   primary partition (1-4)
   

3. Choose an available partition number. In this example the first partition is chosen by entering 1.

   Partition number (1-4): 1

4. Enter the default first cylinder by pressing Enter.

   First cylinder (1-400, default 1):
   

5. Select the size of the partition. In this example the entire disk is allocated by pressing Enter.

   Last cylinder or +size or +sizeM or +sizeK (2-400, default 400):
   

6. Set the type of partition by pressing t.

   Command (m for help): t

7. Choose the partition you created in the previous steps. In this example, the partition number is 1.

   Partition number (1-4): 1

8. Enter 8e for a Linux LVM partition.

   Hex code (type L to list codes): 8e

9. write changes to disk and quit.

   Command (m for help): w
   Command (m for help): q

10. Create a new LVM volume group

    Create a new LVM volume group with the vgcreate command. This example creates a volume group named guest_images_lvm.

    # vgcreate guest_images_lvm /dev/sdb1
      Physical volume "/dev/vdb1" successfully created
      Volume group "guest_images_lvm" successfully created
    

Open the storage pool settings

1. In the virt-manager graphical interface, select the host from the main window.
   Open the Edit menu and select Connection Details
   

   Figure 12.12. Connection details

2. Click on the Storage tab.
   

   Figure 12.13. Storage tab

Create the new storage pool

1. Start the Wizard

   Press the + button (the add pool button). The Add a New Storage Pool wizard appears.
   Choose a Name for the storage pool. We use guest_images_lvm for this example. Then change the Type to logical: LVM Volume Group, and
   

   Figure 12.14. Add LVM storage pool

   Press the Forward button to continue.

2. Add a new pool (part 2)

   Change the Target Path field. This example uses /guest_images.
   Now fill in the Target Path and Source Path fields, then tick the Build Pool check box.
   • Use the Target Path field to either select an existing LVM volume group or as the name for a new volume group. The default format is /dev/storage_pool_name.
     This example uses a new volume group named /dev/guest_images_lvm.
   • The Source Path field is optional if an existing LVM volume group is used in the Target Path.
     For new LVM volume groups, input the location of a storage device in the Source Path field. This example uses a blank partition /dev/sdc.
   • The Build Pool check box instructs virt-manager to create a new LVM volume group. If you are using an existing volume group you should not select the Build Pool check box.
     This example is using a blank partition to create a new volume group so the Build Pool check box must be selected.
   

   Figure 12.15. Add target and source

   Verify the details and press the Finish button format the LVM volume group and create the storage pool.

3. Confirm the device to be formatted

   A warning message appears.
   

   Figure 12.16. Warning message

   Press the Yes button to proceed to erase all data on the storage device and create the storage pool.

Verify the new storage pool

Figure 12.17. Confirm LVM storage pool details