You created a qcow2 file but told libvirt it's type='raw'. Therefore the guest sees a raw file and not a qcow2 file. The qcow2 file is only 196 KB on disk (qemu-img output shows this), this matches with the blocksize --getsize64 output inside the guest.
Change type='raw' to type='qcow2' in your XML and the issue will be resolved.
<driver name='qemu' type='raw' cache=' writethrough' /> home/images/ virtio- scsi23. img'/>
<source file='/
You created a qcow2 file but told libvirt it's type='raw'. Therefore the guest sees a raw file and not a qcow2 file. The qcow2 file is only 196 KB on disk (qemu-img output shows this), this matches with the blocksize --getsize64 output inside the guest.
Change type='raw' to type='qcow2' in your XML and the issue will be resolved.