Here is what happens when taking the default except where just hitting enter would abort the upgrade. Logging all decisions (except the do you really want to do that inside ssh) ... Xenial -> Bionic 3 installed packages are no longer supported by Canonical. You can still get support from the community. 4 packages are going to be removed. 227 new packages are going to be installed. 436 packages are going to be upgraded. You have to download a total of 350 M. This download will take about 1 minute with your connection. Installing the upgrade can take several hours. Once the download has finished, the process cannot be canceled. Continue [yN] Details [d] y 39 packages are going to be removed. Continue [yN] Details [d]d ... Remove: initscripts insserv libbind9-140 libcryptsetup4 libdns-export162 libdns162 libevent-2.0-5 libgdbm3 libicu55 libisc-export160 libisc160 libisccc140 libisccfg140 libjson-c2 liblwres141 libmpfr4 libpng12-0 libprocps4 libpython3.5-minimal libpython3.5-stdlib libreadline6 libxtables11 python3.5 python3.5-minimal sysv-rc Remove (was auto installed) cgmanager libboost-iostreams1.58.0 libboost-random1.58.0 libboost-system1.58.0 libboost-thread1.58.0 libcgmanager0 libnih-dbus1 libpython3.5 libx86-1 libxen-4.6 linux-headers-4.4.0-210 linux-headers-4.4.0-210-generic pm-utils vbetool Continue [yN] Details [d] N Restart required (has to be done to be able to enter the next upgrade) Continue [yN] Y --- # Now Bionic to Focal 16 installed packages are no longer supported by Canonical. You can still get support from the community. 3 packages are going to be removed. 195 new packages are going to be installed. 603 packages are going to be upgraded. You have to download a total of 453 M. This download will take about 1 minute with your connection. Installing the upgrade can take several hours. Once the download has finished, the process cannot be canceled. Continue [yN] Details [d] Remove: btrfs-tools command-not-found-data gcc-5-base gcc-6-base libffi6 libhogweed4 liblvm2app2.2 liblvm2cmd2.02 libnettle6 libnih1 libplymouth4 libvirt-bin ureadahead Remove (was auto installed) augeas-lenses bridge-utils cgmanager ebtables efibootmgr gcc-8-base libargon2-0 libaugeas0 libbind9-160 libbluetooth3 libboost-iostreams1.58.0 libboost-random1.58.0 libboost-system1.58.0 libboost-thread1.58.0 libbrlapi0.6 libcgmanager0 libdns-export1100 libdns1100 libevent-2.1-6 libgdbm5 libicu60 libip4tc0 libip6tc0 libiptc0 libirs160 libisc-export169 libisc169 libisccc160 libisccfg160 libjson-c3 liblwres160 libnetcf1 libnih-dbus1 libntfs-3g88 libperl5.26 libprocps6 libpython3.5 libpython3.6 libpython3.6-minimal libpython3.6-stdlib libreadline7 libsdl1.2debian libvpx5 libx86-1 libxen-4.6 libxen-4.9 libxenstore3.0 libxentoolcore1 linux-headers-4.15.0-213 linux-headers-4.15.0-213-generic linux-headers-4.4.0-210 linux-headers-4.4.0-210-generic linux-image-4.4.0-210-generic linux-modules-4.4.0-210-generic nplan perl-modules-5.26 pm-utils python3-asn1crypto python3-pam python3.6 python3.6-minimal vbetool xdelta3 Continue [yN] Details [d] N Restart required Continue [yN] y $ apt-cache policy libvirt-bin libvirt-clients; virsh -v libvirt-bin: Installed: 4.0.0-1ubuntu8.21 Candidate: 4.0.0-1ubuntu8.21 Version table: *** 4.0.0-1ubuntu8.21 100 100 /var/lib/dpkg/status libvirt-clients: Installed: 6.0.0-0ubuntu8.16 Candidate: 6.0.0-0ubuntu8.16 Version table: *** 6.0.0-0ubuntu8.16 500 500 http://archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages 500 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages 100 /var/lib/dpkg/status 6.0.0-0ubuntu8 500 500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages 6.0.0 # Now Focal to Jammy 13 installed packages are no longer supported by Canonical. You can still get support from the community. 10 packages are going to be removed. 146 new packages are going to be installed. 757 packages are going to be upgraded. You have to download a total of 691 M. This download will take about 2 minutes with your connection. Installing the upgrade can take several hours. Once the download has finished, the process cannot be canceled. Continue [yN] Details [d] y Remove obsolete packages? 120 packages are going to be removed. Removing the packages can take several hours. Continue [yN] Details [d]d Remove: e2fslibs fonts-ubuntu-font-family-console libcomerr2 libfwupdplugin1 libidn11 libldap-2.4-2 libreadline5 libsepol1 lxd lxd-client Remove (was auto installed) augeas-lenses bridge-utils cgmanager crda cryptsetup-run ebtables efibootmgr gcc-10-base gcc-8-base libargon2-0 libaugeas0 libbind9-160 libbluetooth3 libboost-iostreams1.58.0 libboost-iostreams1.71.0 libboost-random1.58.0 libboost-system1.58.0 libboost-thread1.58.0 libboost-thread1.71.0 libbrlapi0.6 libbrlapi0.7 libcanberra0 libcbor0.6 libcgmanager0 libdns-export1100 libdns-export1109 libdns1100 libevent-2.1-6 libevent-2.1-7 libffi7 libfl2 libgdbm5 libgdk-pixbuf-xlib-2.0-0 libgdk-pixbuf2.0-0 libhogweed5 libicu60 libicu66 libip4tc0 libip6tc0 libiptc0 libirs160 libisc-export169 libisc169 libisccc160 libisccfg160 libjson-c3 libjson-c4 libltdl7 liblwres160 libnetcf1 libnettle7 libnih-dbus1 libntfs-3g88 libntfs-3g883 libperl5.30 libprocps6 libpython3.5 libpython3.6 libpython3.6-minimal libpython3.6-stdlib libpython3.8 libpython3.8-minimal libpython3.8-stdlib libreadline7 librest-0.7-0 libsdl1.2debian libsoup-gnome2.4-1 libssl1.1 libtdb1 liburcu6 libvirt-daemon-driver-storage-rbd libvorbisfile3 libvpx5 libvpx6 libwebp6 libx86-1 libxen-4.6 libxen-4.9 libxenstore3.0 libxentoolcore1 libxmlb1 linux-headers-4.15.0-213 linux-headers-4.15.0-213-generic linux-headers-4.4.0-210 linux-headers-4.4.0-210-generic linux-headers-5.4.0-169 linux-headers-5.4.0-169-generic linux-image-4.15.0-213-generic linux-image-4.4.0-210-generic linux-modules-4.15.0-213-generic linux-modules-4.4.0-210-generic linux-modules-extra-4.15.0-213-generic linux-modules-extra-5.4.0-169-generic lz4 nplan perl-modules-5.30 pm-utils python3-asn1crypto python3-entrypoints python3-pam python3-requests-unixsocket python3-simplejson python3.6 python3.6-minimal python3.8 python3.8-minimal sharutils sound-theme-freedesktop vbetool xdelta3 Continue [yN] Details [d] N Restart required Continue [yN] y $ apt-cache policy libvirt-bin libvirt-clients; virsh -v libvirt-bin: Installed: 4.0.0-1ubuntu8.21 Candidate: 4.0.0-1ubuntu8.21 Version table: *** 4.0.0-1ubuntu8.21 100 100 /var/lib/dpkg/status libvirt-clients: Installed: 8.0.0-1ubuntu7.8 Candidate: 8.0.0-1ubuntu7.8 Version table: *** 8.0.0-1ubuntu7.8 500 (phased 10%) 500 http://archive.ubuntu.com/ubuntu jammy-updates/main amd64 Packages 100 /var/lib/dpkg/status 8.0.0-1ubuntu7.5 500 500 http://security.ubuntu.com/ubuntu jammy-security/main amd64 Packages 8.0.0-1ubuntu7 500 500 http://archive.ubuntu.com/ubuntu jammy/main amd64 Packages 8.0.0 So, if paying attention and saying "no" there, it actually is just fine.