Preparing to unpack .../379-zfs-initramfs_0.8.1-pve2_all.deb ...
Unpacking zfs-initramfs (0.8.1-pve2) over (0.7.13-pve1~bpo2) ...
Preparing to unpack .../380-zfsutils-linux_0.8.1-pve2_amd64.deb ...
Unpacking zfsutils-linux (0.8.1-pve2) over (0.7.13-pve1~bpo2) ...
dpkg: error processing archive /tmp/apt-dpkg-install-AkYxng/380-zfsutils-linux_0.8.1-pve2_amd64.deb (--unpack):
 trying to overwrite '/usr/share/man/man5/spl-module-parameters.5.gz', which is also in package spl-dkms 0.7.12-2
Job for zfs-import-cache.service failed.
See "systemctl status zfs-import-cache.service" and "journalctl -xe" for details.
Job for zfs-mount.service failed because the control process exited with error code.
See "systemctl status zfs-mount.service" and "journalctl -xe" for details.
Job for zfs-share.service failed because the control process exited with error code.
See "systemctl status zfs-share.service" and "journalctl -xe" for details.
Preparing to unpack .../381-zfs-zed_0.8.1-pve2_amd64.deb ...
Unpacking zfs-zed (0.8.1-pve2) over (0.7.13-pve1~bpo2) ...
Errors were encountered while processing:
 /tmp/apt-dpkg-install-AkYxng/380-zfsutils-linux_0.8.1-pve2_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)