It seems like it's not easy to write to a place in a qcow2 file using
qemu-io or qemu-img. For example suppose I want to overwrite blocks
100 and 101 with my own data:
$ qemu-img dd -f raw -O qcow2 bs=4096 skip=100 count=2 \
if=/tmp/input.raw of=/tmp/disk.qcow2
qemu-img: /tmp/input.raw: cannot skip to specified offset
Skip is skipping the input, not the output. Turning to qemu-io, it
doesn't look like you can control the data written (only write
patterns).
This patch looks good, but AFAICT it never went upstream:
https://patchwork.kernel.org/patch/9273161/
"qemu-img: add seek option to dd"
Is there anything I'm missing? What is the status of that patch?
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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