[PVE-User] Cannot move disk - "output file is smaller than input file"

[Lindsay Mathieson]

Getting this when trying to move a Ceph RBD image to NFS. 100% reproducable
at the moment.

create full clone of drive ide0 (ceph1:vm-401-disk-1)
Formatting '/mnt/pve/VMSecondary/images/401/vm-401-disk-1.qcow2', fmt=qcow2
size=136365211648 encryption=off cluster_size=65536 preallocation=metadata
lazy_refcounts=off refcount_bits=16
transferred: 0 bytes remaining: 136365211648 bytes total: 136365211648
bytes progression: 0.00 %
qemu-img: output file is smaller than input file
TASK ERROR: storage migration failed: copy failed: command
'/usr/bin/qemu-img convert -t writeback -p -n -f raw -O qcow2
'rbd:rbd/vm-401-disk-1:mon_host=10.10.10.240\:6789;10.10.10.241\:6789;10.10.10.243\:6789;:id=admin:auth_supported=cephx:keyring=/etc/pve/priv/ceph/ceph1.keyring'
zeroinit:/mnt/pve/VMSecondary/images/401/vm-401-disk-1.qcow2' failed: exit
code 1


I've seen this before and worked round it by backing up and restoring, but
I can leave this for a while if needed for testing.


-- 
Lindsay