Home > Storage > PowerMax and VMAX > Storage Admin > Using Dell PowerMax with Linux KVM Implementation Guide > 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 before reuse, KVM fails to create the storage domain. For block volumes, wiping the signature by using the fdisk or dd commands is straightforward. For NFS, however the user might want to keep the existing file system instead of destroying and re-creating it. In the example in Figure 113, one can see the ID of the storage domain that is highlighted in the UI:
Figure 113. Storage domain ID
A folder on the file system represents this ID, as shown in Figure 114:
Figure 114. The “ID folder” for the NFS storage domain
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 an error, as shown in Figure 115:
Figure 115. Error creating NFS storage domain
If the user receives this error message but knows that they want to reuse the file system, they can remove the folder. The easiest way is to mount the NFS export on another Windows or Linux host and deleting the “ID folder.” When the folder is removed, retrying the operation succeeds.
Note: The file system does not have to be empty before creating a storage domain on it, however, it cannot contain an “ID folder.”