[Libguestfs] Checksums and other verification
https://github.com/kubevirt/containerized-data-importer/issues/1520
Hi Eric,
We had a question from the Kubevirt team related to the above issue.
The question is roughly if it's possible to calculate the checksum of
an image as an nbdkit filter and/or in the qemu block layer.
Supplemental #1: could qemu-img convert calculate a checksum as it goes
along?
Supplemental #2: could we detect various sorts of common errors, such
a webserver that is incorrectly configured and serves up an error page
containing "<html>"; or something which is supposed to be a disk image
but does not "look like" (in some ill-defined sense) a disk image,
eg. it has no partition table.
I'm not sure if qemu has any existing features covering the above (and
I know for sure that nbdkit doesn't).
One issue is that calculating a checksum involves a linear scan of the
image, although we can at least skip holes.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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