How to use the command "virsh-pool-build" (with examples)

Code:

virsh pool-build --pool pool1

Motivation:

This command is used to build the underlying storage system for a virtual machine storage pool. By executing this command, we can ensure that the virtual machine storage pool is ready for use.

Explanation:

• pool-build: This is the command to build the storage system for a virtual machine storage pool.
• --pool: This option specifies the name or UUID of the storage pool to be built. The name or UUID can be determined using the virsh pool-list command.

Example Output:

The storage pool 'pool1' has been successfully built.

Use Case 2: Building a storage pool using UUID

Code:

virsh pool-build --pool 8f5b1ed6-3c6e-49e8-a52f-f2651c83632d

Motivation:

In some cases, we might not know the name of the storage pool, but we have the UUID. This command allows us to build the storage pool using the UUID instead of the name.

Explanation:

• pool-build: This is the command to build the storage system for a virtual machine storage pool.
• --pool: This option specifies the UUID of the storage pool to be built.

Example Output:

The storage pool with UUID '8f5b1ed6-3c6e-49e8-a52f-f2651c83632d' has been successfully built.

Use Case 3: Building a storage pool using a variable

Code:

pool_name="pool2"
virsh pool-build --pool $pool_name

Motivation:

In a script or automation tool, it might be useful to build a storage pool based on a dynamic value or variable. This use case demonstrates how to use a variable to specify the name of the storage pool.

Explanation:

• pool-build: This is the command to build the storage system for a virtual machine storage pool.
• --pool: This option specifies the name of the storage pool to be built.

Example Output:

The storage pool 'pool2' has been successfully built.

Use Case 4: Building multiple storage pools

Code:

virsh pool-build --pool pool1
virsh pool-build --pool pool2
virsh pool-build --pool pool3

Motivation:

In scenarios where we need to build multiple storage pools, we can execute the virsh pool-build command multiple times by specifying different pool names or UUIDs. This allows us to build multiple storage pools in a single script or session.

Explanation:

• pool-build: This is the command to build the storage system for a virtual machine storage pool.
• --pool: This option specifies the name or UUID of the storage pool to be built.

Example Output:

The storage pool 'pool1' has been successfully built.
The storage pool 'pool2' has been successfully built.
The storage pool 'pool3' has been successfully built.

Use Case 5: Building a storage pool by name and UUID simultaneously

Code:

virsh pool-build --pool pool1
virsh pool-build --pool 8f5b1ed6-3c6e-49e8-a52f-f2651c83632d

Motivation:

In some cases, we might need to build a storage pool using both the name and UUID. This use case demonstrates how to build a storage pool by specifying both the name and UUID.

Explanation:

• pool-build: This is the command to build the storage system for a virtual machine storage pool.
• --pool: This option specifies the name or UUID of the storage pool to be built.

Example Output:

The storage pool 'pool1' has been successfully built.
The storage pool with UUID '8f5b1ed6-3c6e-49e8-a52f-f2651c83632d' has been successfully built.

Use Case 6: Building a default storage pool

Code:

virsh pool-build --pool default

Motivation:

By default, Libvirt provides a storage pool called “default” that is configured with a basic file backend. This use case demonstrates how to build the default storage pool.

Explanation:

• pool-build: This is the command to build the storage system for a virtual machine storage pool.
• --pool: This option specifies the name of the storage pool to be built.

Example Output:

The storage pool 'default' has been successfully built.

Use Case 7: Building a storage pool with a dynamically created pool definition file

Code:

echo '
<pool type="dir">
  <name>newpool</name>
  <target>
    <path>/var/lib/libvirt/newpool</path>
  </target>
</pool>
' > /tmp/newpool.xml

virsh pool-define /tmp/newpool.xml
virsh pool-build --pool newpool

Motivation:

In some cases, we might need to build a storage pool using a dynamically created pool definition file. This use case demonstrates how to create a pool definition file, define the pool using virsh pool-define, and then build the storage pool.

Explanation:

• pool-build: This is the command to build the storage system for a virtual machine storage pool.
• --pool: This option specifies the name of the storage pool to be built.

Example Output:

The storage pool 'newpool' has been successfully built.

Use Case 8: Building a storage pool using the libvirt API

Code:

import libvirt

conn = libvirt.open("qemu:///system")
pool = conn.storagePoolLookupByName("pool1")
pool.build()

Motivation:

In applications or scripts that use the libvirt API, we can build a storage pool programmatically using the libvirt Python library. This use case demonstrates how to build a storage pool using the libvirt API.

Explanation:

• libvirt.open("qemu:///system"): This establishes a connection to the libvirt daemon.
• conn.storagePoolLookupByName("pool1"): This retrieves the storage pool object with the name “pool1”.
• pool.build(): This method builds the underlying storage system for the storage pool.

Example Output:

No output is shown, but the storage pool is successfully built.