Virsh vol-create-as

External

• RHEL7 Virtualization Administration - Creating Storage Volumes from Parameters

Internal

• virsh
• Virtualization Operations - Storage Volume Creation

Overview

Creates a storage volume.

Creation from Command Line Parameters

virsh vol-create-as --pool <pool-name> --name <volume-name> --capacity <capacity> --format <fomat>

Naming Convention

Storage Volume Naming Convention

Options

--pool

The pool name or pool UUID. The "--pool" label is optional if the pool name is specified as the first argument.

--name

The storage volume name. The "--name" label is optional if the storage volume name is specified as the second argument.

--capacity

The capacity, followed by one of the suffixes 'b', 'k', 'M', 'G', 'T'. The capacity is specified in bytes if there is no suffix. The "--capacity" label is optional if the capacity is specified as the third argument.

--print-xml

If specified, the volume is not created, only the XML of the volume object is printed out.

--allocation

The initial size to be allocated in the volume, as a scaled integer defaulting to bytes.

--format

Acceptable format types: "raw", "bochs", "qcow", "qcow2", "qed", "host_device", and "vmdk". These are, however, only meant for file based storage pools. By default the qcow version that is used is version 3.

--backing-vol

The source backing volume to be used if taking a snapshot of an existing volume.

--backing-vol-format

The format of the snapshot backing volume; raw, bochs, qcow, qcow2, qed, vmdk, host_device.

--prealloc-metadata

Preallocate metadata for qcow2 images that don't support full allocation. This option creates a sparse image file with metadata, resulting in higher performance compared to images with no preallocation and only slightly higher initial disk space usage.

Examples

Create a New Raw Block Storage Volume

virsh vol-create-as --pool main-storage-pool --name test-nfs.raw --capacity 1G --format raw

See Storage Volume Naming Convention.

Creation from a Saved Definition

Volumes can be created from an XML definition file produced by a previous virsh vol-dumpxml command.

virsh vol-create <pool-name> ./volume-definition-file.xml 

virsh vol-create main-storage-pool ./node3.qcow2.xml

Note that at the moment of creation, the qcow2 volumes are empty, while the raw volumes show as fully allocated.