After run apt-get dist-upgrade then reboot, I got error:
- Kernel Panic ... line 10: can't not open /etc/zfs/zfs-functions
See image for details error. Any idea to fix this?
if that is your most recent kernel version, than you did not do a complete dist-upgrade (the current PVE 3.4 2.6.32 kernel is 2.6.32-46-pve). the missing file it is complaining about is part of zfsutils, and referenced in zfs-initramfs and zfsutils - maybe something went wrong with upgrading either of those?
I am afraid you will have to boot with a zfs capable live medium to investigate further:
chroot and do a complete dist-upgrade
check whether /etc/zfs/zfs-functions
check and potentially regenerate the initramfs (also needs to contain /etc/zfs/zfs-functions)