12.2.3. Creating a Partition-based Storage Pool Using virsh

Procedure 12.2. Creating pre-formatted block device storage pools using virsh

1. Create the storage pool definition

   Use the virsh pool-define-as command to create a new storage pool definition. There are three options that must be provided to define a pre-formatted disk as a storage pool:

   Partition name

   The name parameter determines the name of the storage pool. This example uses the name guest_images_fs in the example below.

   device

   The device parameter with the path attribute specifies the device path of the storage device. This example uses the partition /dev/sdc1.

   mountpoint

   The mountpoint on the local file system where the formatted device will be mounted. If the mount point directory does not exist, the virsh command can create the directory.

   The directory /guest_images is used in this example.

   # virsh pool-define-as guest_images_fs fs - - /dev/sdc1 - "/guest_images"
   Pool guest_images_fs defined
   

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   The new pool and mount points are now created.

2. Verify the new pool

   List the present storage pools.

   # virsh pool-list --all
   Name                 State      Autostart
   -----------------------------------------
   default              active     yes
   guest_images_fs      inactive   no
   

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3. Create the mount point

   Use the virsh pool-build command to create a mount point for a pre-formatted file system storage pool.

   # virsh pool-build guest_images_fs
   Pool guest_images_fs built
   # ls -la /guest_images
   total 8
   drwx------.  2 root root 4096 May 31 19:38 .
   dr-xr-xr-x. 25 root root 4096 May 31 19:38 ..
   # virsh pool-list --all
   Name                 State      Autostart
   -----------------------------------------
   default              active     yes
   guest_images_fs      inactive   no
   

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4. Start the storage pool

   Use the virsh pool-start command to mount the file system onto the mount point and make the pool available for use.

   # virsh pool-start guest_images_fs
   Pool guest_images_fs started
   # virsh pool-list --all
   Name                 State      Autostart
   -----------------------------------------
   default              active     yes
   guest_images_fs      active     no
   

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5. Turn on autostart

   By default, a storage pool defined with virsh, is not set to automatically start each time libvirtd starts. To remedy this, enable the automatic start with the virsh pool-autostart command. The storage pool is now automatically started each time libvirtd starts.

   # virsh pool-autostart guest_images_fs
   Pool guest_images_fs marked as autostarted
   
   # virsh pool-list --all
   Name                 State      Autostart
   -----------------------------------------
   default              active     yes
   guest_images_fs      active     yes
   

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6. Verify the storage pool

   Verify the storage pool was created correctly, the sizes reported are as expected, and the state is reported as running. Verify there is a "lost+found" directory in the mount point on the file system, indicating the device is mounted.

   # virsh pool-info guest_images_fs
   Name:           guest_images_fs
   UUID:           c7466869-e82a-a66c-2187-dc9d6f0877d0
   State:          running
   Persistent:     yes
   Autostart:      yes
   Capacity:       458.39 GB
   Allocation:     197.91 MB
   Available:      458.20 GB
   # mount | grep /guest_images
   /dev/sdc1 on /guest_images type ext4 (rw)
   # ls -la /guest_images
   total 24
   drwxr-xr-x.  3 root root  4096 May 31 19:47 .
   dr-xr-xr-x. 25 root root  4096 May 31 19:38 ..
   drwx------.  2 root root 16384 May 31 14:18 lost+found
   

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