I have a server at home that tends to be install and forget. It's running Wheezy and zfsonlinux. Unfortunately zfsonlinux no longer supports Wheezy, so upgrading isn't as straight-forward as I would hope. I am following instructions at https://www.howtoforge.com/ tutorial/how-to-upgrade-debian-wheezy-to-jessie-stable-release/ and one of the early steps is to do apt-get update which gets some "No public key available" for the zfsonlinux/wheezy links. This leads to the following: root@server:/etc/apt# apt-get upgrade Reading package lists... Done Building dependency tree Reading state information... Done The following packages have been kept back: default-jdk default-jre default-jre-headless zfsutils The following packages will be upgraded: apt apt-utils base-files bash bind9-host binutils cpio cups cups-client cups-common cups-filters cups-ppdc dbus debian-archive-keyring dnsutils dpkg dpkg-dev e2fslibs e2fsprogs exim4 exim4-base exim4-config exim4-daemon-light file fontconfig fontconfig-config foomatic-filters ghostscript ghostscript-cups gnupg gpgv grub-common grub-pc grub-pc-bin grub2-common gstreamer0.10-gconf gstreamer0.10-plugins-bad gstreamer0.10-plugins-base gstreamer0.10-plugins-good gstreamer0.10-x host hpijs hplip hplip-data icedtea-6-jre-cacao icedtea-6-jre-jamvm icedtea-netx icedtea-netx-common isc-dhcp-client isc-dhcp-common java-common krb5-locales libapt-inst1.5 libapt-pkg4.12 libass4 libavcodec53 libavformat53 libavutil51 libbind9-80 libc-bin libc-dev-bin libc6 libc6-dev libcairo-gobject2 libcairo2 libcomerr2 libcups2 libcupscgi1 libcupsdriver1 libcupsfilters1 libcupsimage2 libcupsmime1 libcupsppdc1 libcurl3-gnutls libdbus-1-3 libdns88 libdpkg-perl libevent-2.0-5 libexpat1 libfontconfig1 libfreetype6 libfuse2 libgc1c2 libgcrypt11 libgd2-xpm libgdk-pixbuf2.0-0 libgdk-pixbuf2.0-common libgif4 libgme0 libgnutls-openssl27 libgnutls26 libgs9 libgs9-common libgssapi-krb5-2 libgssrpc4 libgstreamer-plugins-bad0.10-0 libgstreamer-plugins-base0.10-0 libgtk-3-0 libgtk-3-bin libgtk-3-common libhpmud0 libicu48 libidn11 libisc84 libisccc80 libisccfg82 libjasper1 libk5crypto3 libkadm5clnt-mit8 libkadm5srv-mit8 libkdb5-6 libkrb5-3 libkrb5support0 liblcms1 liblcms2-2 libldap-2.4-2 liblwres80 libmagic1 libnspr4 libnss3 libnvpair1 libpcsclite1 libperl5.14 libpixman-1-0 libpng12-0 libpoppler19 libpython2.7 librsvg2-2 librsvg2-common libsane-hpaio libslp1 libsqlite3-0 libss2 libssl1.0.0 libsystemd-login0 libtasn1-3 libtiff4 libupnp6 libuutil1 libx11-6 libx11-data libx11-dev libx11-doc libx11-xcb1 libxapian22 libxfixes3 libxi6 libxml2 libxpm4 libxrandr2 libxrender1 libxslt1.1 libxtst6 libxv1 libzfs2 libzpool2 linux-headers-3.2.0-4-amd64 linux-headers-3.2.0-4-common linux-image-3.2.0-4-amd64 linux-libc-dev live-tools locales mime-support multiarch-support openjdk-6-jdk openjdk-6-jre openjdk-6-jre-headless openjdk-6-jre-lib openssh-client openssh-server openssl perl perl-base perl-modules poppler-utils printer-driver-hpcups printer-driver-hpijs printer-driver-postscript-hp python-crypto python-imaging python2.7 python2.7-minimal rpcbind spl spl-dkms ssl-cert sudo tar tzdata tzdata-java unzip vim-common vim-tiny wget wpasupplicant xscreensaver xscreensaver-data zfs-dkms zfsonlinux 199 upgraded, 0 newly installed, 0 to remove and 4 not upgraded. Need to get 217 MB of archives. After this operation, 4,578 kB disk space will be freed. Do you want to continue [Y/n]? WARNING: The following packages cannot be authenticated! zfs-dkms zfsonlinux libuutil1 libnvpair1 libzpool2 libzfs2 grub-pc grub-pc-bin grub2-common grub-common spl spl-dkms Install these packages without verification [y/N]? E: Some packages could not be authenticated And nothing happens. I guess I have to tell it not to try to upgrade those unauthenticated packages, but I don't know how. Any advice appreciated. Thanks ../Dave