On 2017-09-18 14:42, Pavel Butsykin wrote: > This patch add shrinking of the image file for qcow2. As a result, this allows > us to reduce the virtual image size and free up space on the disk without > copying the image. Image can be fragmented and shrink is done by punching > holes > in the image file. > > # ./qemu-img create -f qcow2 image.qcow2 4G > Formatting 'image.qcow2', fmt=qcow2 size=4294967296 encryption=off > cluster_size=65536 lazy_refcounts=off refcount_bits=16 > > # ./qemu-io -c "write -P 0x22 0 1G" image.qcow2 > wrote 1073741824/1073741824 bytes at offset 0 > 1 GiB, 1 ops; 0:00:04.59 (222.886 MiB/sec and 0.2177 ops/sec) > > # ./qemu-img resize image.qcow2 512M > warning: qemu-img: Shrinking an image will delete all data beyond the > shrunken image's end. Before performing such an operation, make sure there is > no important data there. > error: qemu-img: Use the --shrink option to perform a shrink operation. > > # ./qemu-img resize --shrink image.qcow2 128M > Image resized. > > # ./qemu-img info image.qcow2 > image: image.qcow2 > file format: qcow2 > virtual size: 128M (134217728 bytes) > disk size: 128M > cluster_size: 65536 > Format specific information: > compat: 1.1 > lazy refcounts: false > refcount bits: 16 > corrupt: false > > # du -h image.qcow2 > 129M image.qcow2
Thanks, I've added the missing space in patch 1 and applied the series to my block branch: https://github.com/XanClic/qemu/commits/block Max
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