I exported a VM to a disk image using iohyve export (code: see iohyve/lib/ioh-zfs at 29504048aa623186e9a0703604f666df44cfacb8 · pr1ntf/iohyve · GitHub ) and the dd’ed VM images which I got contain files modified in 2019. I am wondering if the dd command is referencing the “base” oldest snapshot and not the latest snapshot. What’s strange is that the earliest snapshots I see are from Jan 2021.
I am contemplating deleting all snapshots up to the end of 2024 (definitely don’t need them) and then doing the export again… would that help? Does deleting old snapshots bring the “base” zvol into a state where it is essentially at the earliest snapshot? I need to export a VM state from sometime Jan-March 2025.
I tried understanding How ZFS snapshots really work and why they perform well (usually) :: FreeBSD Presentations and Papers but that lost me a bit.
I’d also happily take a dd command that lets me dump the zvol state at a certain snapshot time. All the images I generated were either very small, or did not boot.