Howto automatically create a snapshot before installing new packages with apt

/usr/local/sbin/apt-zfs-snapshot

#!/bin/sh

ZFS_POOL="rpool"
SNAPNAME="apt-upgrade-$(date +%Y%m%d-%H%M%S)"

# Create snapshot
/sbin/zfs snapshot -r ${ZFS_POOL}@${SNAPNAME}

# Cleanup: keep last 10 snapshots
/sbin/zfs list -H -t snapshot -o name -s creation | \
   grep "${ZFS_POOL}@apt-upgrade" | head -n -10 | \
   xargs -r /sbin/zfs destroy

exit 0

/etc/apt/apt.conf.d/90zfs-snapshot

DPkg::Pre-Install-Pkgs { "/usr/local/sbin/apt-zfs-snapshot"; };

niet vergeten!

chmod +x /usr/local/sbin/apt-zfs-snapshot