qemu-img create -f qcow2 -o preallocation=metadata  oracle1_2.qcow2 10G

qemu-img resize ./oracle_okv1_1.qcow2 +50G
 
Image resized.

qemu-img info ./oracle_okv1_1.qcow2
 
image: ./oracle_okv1_1.qcow2
file format: qcow2
virtual size: 400 GiB (429496729600 bytes)
disk size: 42.3 GiB
cluster_size: 65536
Format specific information:
    compat: 1.1
    compression type: zlib
    lazy refcounts: false
    refcount bits: 16
    corrupt: false
    extended l2: false
Child node '/file':
    filename: ./oracle_okv1_1.qcow2
    protocol type: file
    file length: 350 GiB (375867244544 bytes)
    disk size: 42.3 GiB
    Format specific information:
        extent size hint: 1048576