Home > Storage > PowerFlex > White Papers > Using Dell PowerFlex with Linux KVM > Existing NFS storage domain
Reusing an existing block device or file system with KVM is common. When KVM creates a storage domain, an ID is assigned. If that ID is not removed prior to reuse, KVM fails to create the storage domain. For block volumes, wiping the signature with fdisk or dd is straightforward. For NFS, however, a customer may want to keep the existing file system instead of destroying and re-creating it. For example, here in Figure 94, one can see the ID of the storage domain that is highlighted in the UI.
This ID is represented by a folder on the file system as demonstrated in Figure 95.
Each storage domain, therefore, is unique. If an attempt is made to mount an NFS export that already has an “ID folder,” it fails and generates the error in Figure 96.
If the user receives this error but knows that they want to reuse the file system, they can remove the folder. This is most easily accomplished by mounting the NFS export on another host, Windows or Linux, and deleting the “ID folder.” Once the folder is removed, a retry of the operation succeeds.
Note: The file system does not have to be empty before creating a storage domain on it, but it cannot contain an “ID folder.”