Chapter 14. Storage Volumes
14.1.1. Referencing Volumes
- The name of the volume and the storage pool
- A volume may be referred to by name, along with an identifier for the storage pool it belongs in. On the virsh command line, this takes the form
--poolstorage_pool volume_name.For example, a volume named firstimage in the guest_images pool.
virsh vol-info --pool guest_images firstimageName: firstimage Type: block Capacity: 20.00 GB Allocation: 20.00 GB virsh #
- The full path to the storage on the host physical machine system
- A volume may also be referred to by its full path on the file system. When using this approach, a pool identifier does not need to be included.For example, a volume named secondimage.img, visible to the host physical machine system as /images/secondimage.img. The image can be referred to as /images/secondimage.img.
virsh vol-info /images/secondimage.imgName: secondimage.img Type: file Capacity: 20.00 GB Allocation: 136.00 kB
- The unique volume key
- When a volume is first created in the virtualization system, a unique identifier is generated and assigned to it. The unique identifier is termed the volume key. The format of this volume key varies upon the storage used.When used with block-based storage such as LVM, the volume key may follow this format:
c3pKz4-qPVc-Xf7M-7WNM-WJc8-qSiz-mtvpGnWhen used with file-based storage, the volume key may instead be a copy of the full path to the volume storage.
/images/secondimage.imgFor example, a volume with the volume key of Wlvnf7-a4a3-Tlje-lJDa-9eak-PZBv-LoZuUr:
virsh vol-info Wlvnf7-a4a3-Tlje-lJDa-9eak-PZBv-LoZuUrName: firstimage Type: block Capacity: 20.00 GB Allocation: 20.00 GB
virshprovides commands for converting between a volume name, volume path, or volume key:
- Returns the volume name when provided with a volume path or volume key.
virsh vol-name /dev/guest_images/firstimagefirstimage #
virsh vol-name Wlvnf7-a4a3-Tlje-lJDa-9eak-PZBv-LoZuUr
- Returns the volume path when provided with a volume key, or a storage pool identifier and volume name.
virsh vol-path Wlvnf7-a4a3-Tlje-lJDa-9eak-PZBv-LoZuUr/dev/guest_images/firstimage #
virsh vol-path --pool guest_images firstimage/dev/guest_images/firstimage
- The vol-key command
- Returns the volume key when provided with a volume path, or a storage pool identifier and volume name.
virsh vol-key /dev/guest_images/firstimageWlvnf7-a4a3-Tlje-lJDa-9eak-PZBv-LoZuUr #
virsh vol-key --pool guest_images firstimageWlvnf7-a4a3-Tlje-lJDa-9eak-PZBv-LoZuUr