18 libguestfs #

Full step-by-step example: How to expand a virtual machine disk

1. First, with virtual machine powered off, determine the size of the partitions available on this virtual machine:

   > virt-filesystems --long --parts --blkdevs -h -a sles.qcow2
   Name       Type       MBR  Size  Parent
   /dev/sda1  partition  83   16G   /dev/sda
   /dev/sda   device     -    16G   -

2. virt-resize cannot do in-place disk modifications—there must be sufficient space to store the resized output disk. Use the truncate command to create a file of suitable size:

   > truncate -s 32G outdisk.img

3. Use virt-resize to resize the disk image. virt-resize requires two mandatory parameters for the input and output images:

   > virt-resize --expand /dev/sda1 sles.qcow2 outdisk.img
   Examining sles.qcow2 ...
   **********
   Summary of changes:
   
   /dev/sda1: This partition will be resized from 16,0G to 32,0G.  The
       filesystem ext3 on /dev/sda1 will be expanded using the 'resize2fs'
       method.
   
   **********
   Setting up initial partition table on outdisk.img ...
   Copying /dev/sda1 ...
   ◐ 84%
   ⟦▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒════════⟧ 00:03
   Expanding /dev/sda1 using the 'resize2fs' method ...
   
   Resize operation completed with no errors.  Before deleting the old
   disk, carefully check that the resized disk boots and works correctly.

4. Confirm the image was resized properly:

   > virt-filesystems --long --parts --blkdevs -h -a outdisk.img
   Name       Type       MBR  Size  Parent
   /dev/sda1  partition  83   32G   /dev/sda
   /dev/sda   device     -    32G   -

5. Bring up the VM Guest using the new disk image and confirm correct operation before deleting the old image.

1. Install the needed packages with the command:

   > sudo zypper in virt-p2v kiwi-desc-isoboot

   

   Note

   These steps will document how to create an ISO image to create a bootable DVD. Alternatively, you can create a PXE boot image instead; for more information about building PXE images with KIWI, see man virt-p2v-make-kiwi.

2. Create a KIWI configuration:

   > virt-p2v-make-kiwi -o /tmp/p2v.kiwi

   The -o defines where to create the KIWI configuration.

3. Edit the config.xml file in the generated configuration if needed. For example, in config.xml adjust the keyboard layout of the live system.

4. Build the ISO image with kiwi:

   > kiwi --build /tmp/p2v.kiwi1 \
        -d /tmp/build2 \
        --ignore-repos \
        --add-repo http://URL/TO/SLE/REPOSITORIES3 \
        --type iso

   1	The directory where the KIWI configuration was generated in the previous step.
   2	The directory where KIWI will place the generated ISO image and other intermediary build results.
   3	The URLs to the package repositories as found with zypper lr -d. Use one --add-repo parameter per repository.

5. Burn the ISO on a DVD or a USB stick. With such a medium, boot the machine to be converted.

6. After the system is started, you will be asked for the connection details of the conversion server. This server is a machine with the virt-v2v package installed.

   If the network setup is more complex than a DHCP client, click the Configure network button to open the YaST network configuration dialog.

   Click the Test connection button to allow moving to the next page of the wizard.

7. Select the disks and network interfaces to be converted and define the VM data like the amount of allocated CPUs, memory and the Virtual Machine name.

   

   Note

   If not defined, the created disk image format will be raw by default. This can be changed by entering the desired format in the Output format field.

   There are two possibilities to generate the virtual machine: either using the local or the libvirt output. The first one will place the Virtual Machine disk image and configuration in the path defined in the Output storage field. These can then be used to define a new libvirt-handled guest using virsh. The second method will create a new libvirt-handled guest with the disk image placed in the pool defined in the Output storage field.

   Click Start conversion to start it.