Restoring a QEMU snapshot

[Patrick O'Callaghan]

I have a QEMU image snapshot:

$ sudo qemu-img info /var/lib/libvirt/images/Windows10.qcow2         
image: /var/lib/libvirt/images/Windows10.qcow2
file format: qcow2
virtual size: 20G (21474836480 bytes)
disk size: 196K
cluster_size: 65536
backing file: /home/poc/Win10/win10.qcow2
backing file format: qcow2
Format specific information:
    compat: 1.1
    lazy refcounts: true
    refcount bits: 16
    corrupt: false

However when I try to restore the virtual disk I get:

$ sudo qemu-img snapshot -a /var/lib/libvirt/images/Windows10.qcow2
/home/poc/Win10/win10.qcow2        
qemu-img: Could not apply snapshot '/var/lib/libvirt/images/Windows10.qcow2': -2
(No such file or directory)

I must be doing something obviously wrong, but can't see what it is.
Hints would be appreciated.

poc