Qemu-img Differences between Snapshots

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Revision as of 18:42, 18 December 2017 by Ovidiu (talk | contribs) (→‎Procedure)
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Overview

This is a procedure that can be used to list differences between qemu-img snapshots. It is probably not optimal, and there are probably tools that do this better, but at the time of the writing, I did not know about them.

Procedure

1. Take a snapshot of the filesystem before the event whose effects you want to analyze: qemu-img snapshot -c ...

2. Trigger the event.

3. Save the state of the filesystem after the event, by cloning the filesystem, with virsh vol-clone, after the VM guest has been shut down:

virsh vol-clone --pool main-storage-pool --prealloc-metadata build-guest.qcow2 build-guest-after.qcow2