Just happened to me too: root@gw:/etc# apt upgrade Reading package lists... Done Building dependency tree Reading state information... Done Calculating upgrade... Done The following packages were automatically installed and are no longer required: eatmydata libeatmydata1 python3-blinker python3-jinja2 python3-json-pointer python3-jsonpatch python3-jsonschema python3-jwt python3-markupsafe python3-oauthlib Use 'apt autoremove' to remove them. The following packages will be upgraded: apport busybox-initramfs busybox-static docker.io initramfs-tools initramfs-tools-bin initramfs-tools-core landscape-common libidn11 libnss-systemd libpam-modules libpam-modules-bin libpam-runtime libpam-systemd libpam0g libpci3 libseccomp2 libsystemd0 libudev1 libx11-6 libx11-data libxcb1 pciutils python3-apport python3-gi python3-problem-report systemd systemd-sysv udev unattended-upgrades 30 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. Need to get 54.0 MB of archives. After this operation, 37.2 MB of additional disk space will be used. Do you want to continue? [Y/n] y Get:1 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libpam0g amd64 1.1.8-3.6ubuntu2.18.04.1 [55.1 kB] Get:2 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libpam-modules-bin amd64 1.1.8-3.6ubuntu2.18.04.1 [36.7 kB] Get:3 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libpam-modules amd64 1.1.8-3.6ubuntu2.18.04.1 [242 kB] Get:4 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libnss-systemd amd64 237-3ubuntu10.15 [105 kB] Get:5 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libsystemd0 amd64 237-3ubuntu10.15 [205 kB] Get:6 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libpam-systemd amd64 237-3ubuntu10.15 [108 kB] Get:7 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 systemd amd64 237-3ubuntu10.15 [2,899 kB] Get:8 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 udev amd64 237-3ubuntu10.15 [1,100 kB] Get:9 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libudev1 amd64 237-3ubuntu10.15 [54.2 kB] Get:10 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libpam-runtime all 1.1.8-3.6ubuntu2.18.04.1 [37.1 kB] Get:11 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 initramfs-tools all 0.130ubuntu3.7 [9,592 B] Get:12 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 initramfs-tools-core all 0.130ubuntu3.7 [48.1 kB] Get:13 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 initramfs-tools-bin amd64 0.130ubuntu3.7 [12.8 kB] Get:14 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 busybox-initramfs amd64 1:1.27.2-2ubuntu3.1 [166 kB] Get:15 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 systemd-sysv amd64 237-3ubuntu10.15 [12.0 kB] Get:16 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libseccomp2 amd64 2.3.1-2.1ubuntu4.1 [39.1 kB] Get:17 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libidn11 amd64 1.33-2.1ubuntu1.1 [45.9 kB] Get:18 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 python3-gi amd64 3.26.1-2ubuntu1 [153 kB] Get:19 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 busybox-static amd64 1:1.27.2-2ubuntu3.1 [918 kB] Get:20 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 pciutils amd64 1:3.5.2-1ubuntu1.1 [257 kB] Get:21 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libpci3 amd64 1:3.5.2-1ubuntu1.1 [24.1 kB] Get:22 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libx11-data all 2:1.6.4-3ubuntu0.2 [113 kB] Get:23 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libxcb1 amd64 1.13-2~ubuntu18.04 [45.5 kB] Get:24 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libx11-6 amd64 2:1.6.4-3ubuntu0.2 [569 kB] Get:25 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 python3-problem-report all 2.20.9-0ubuntu7.6 [9,884 B] Get:26 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 python3-apport all 2.20.9-0ubuntu7.6 [81.7 kB] Get:27 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 apport all 2.20.9-0ubuntu7.6 [124 kB] Get:28 http://hu.archive.ubuntu.com/ubuntu bionic-updates/universe amd64 docker.io amd64 18.09.2-0ubuntu1~18.04.1 [46.4 MB] Get:29 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 landscape-common amd64 18.01-0ubuntu3.3 [85.3 kB] Get:30 http://hu.archive.ubuntu.com/ubuntu bionic-updates/main amd64 unattended-upgrades all 1.1ubuntu1.18.04.9 [40.0 kB] Fetched 54.0 MB in 5s (11.2 MB/s) Preconfiguring packages ... (Reading database ... 115046 files and directories currently installed.) Preparing to unpack .../libpam0g_1.1.8-3.6ubuntu2.18.04.1_amd64.deb ... Unpacking libpam0g:amd64 (1.1.8-3.6ubuntu2.18.04.1) over (1.1.8-3.6ubuntu2) ... Setting up libpam0g:amd64 (1.1.8-3.6ubuntu2.18.04.1) ... (Reading database ... 115046 files and directories currently installed.) Preparing to unpack .../libpam-modules-bin_1.1.8-3.6ubuntu2.18.04.1_amd64.deb ... Unpacking libpam-modules-bin (1.1.8-3.6ubuntu2.18.04.1) over (1.1.8-3.6ubuntu2) ... Setting up libpam-modules-bin (1.1.8-3.6ubuntu2.18.04.1) ... (Reading database ... 115046 files and directories currently installed.) Preparing to unpack .../libpam-modules_1.1.8-3.6ubuntu2.18.04.1_amd64.deb ... Unpacking libpam-modules:amd64 (1.1.8-3.6ubuntu2.18.04.1) over (1.1.8-3.6ubuntu2) ... Setting up libpam-modules:amd64 (1.1.8-3.6ubuntu2.18.04.1) ... (Reading database ... 115046 files and directories currently installed.) Preparing to unpack .../libnss-systemd_237-3ubuntu10.15_amd64.deb ... Unpacking libnss-systemd:amd64 (237-3ubuntu10.15) over (237-3ubuntu10.13) ... Preparing to unpack .../libsystemd0_237-3ubuntu10.15_amd64.deb ... Unpacking libsystemd0:amd64 (237-3ubuntu10.15) over (237-3ubuntu10.13) ... Setting up libsystemd0:amd64 (237-3ubuntu10.15) ... (Reading database ... 115046 files and directories currently installed.) Preparing to unpack .../libpam-systemd_237-3ubuntu10.15_amd64.deb ... Unpacking libpam-systemd:amd64 (237-3ubuntu10.15) over (237-3ubuntu10.13) ... Preparing to unpack .../systemd_237-3ubuntu10.15_amd64.deb ... Unpacking systemd (237-3ubuntu10.15) over (237-3ubuntu10.13) ... Preparing to unpack .../udev_237-3ubuntu10.15_amd64.deb ... Unpacking udev (237-3ubuntu10.15) over (237-3ubuntu10.13) ... Preparing to unpack .../libudev1_237-3ubuntu10.15_amd64.deb ... Unpacking libudev1:amd64 (237-3ubuntu10.15) over (237-3ubuntu10.13) ... Setting up libudev1:amd64 (237-3ubuntu10.15) ... (Reading database ... 115046 files and directories currently installed.) Preparing to unpack .../libpam-runtime_1.1.8-3.6ubuntu2.18.04.1_all.deb ... Unpacking libpam-runtime (1.1.8-3.6ubuntu2.18.04.1) over (1.1.8-3.6ubuntu2) ... Setting up libpam-runtime (1.1.8-3.6ubuntu2.18.04.1) ... (Reading database ... 115046 files and directories currently installed.) Preparing to unpack .../initramfs-tools_0.130ubuntu3.7_all.deb ... Unpacking initramfs-tools (0.130ubuntu3.7) over (0.130ubuntu3.6) ... Preparing to unpack .../initramfs-tools-core_0.130ubuntu3.7_all.deb ... Unpacking initramfs-tools-core (0.130ubuntu3.7) over (0.130ubuntu3.6) ... Preparing to unpack .../initramfs-tools-bin_0.130ubuntu3.7_amd64.deb ... Unpacking initramfs-tools-bin (0.130ubuntu3.7) over (0.130ubuntu3.6) ... Preparing to unpack .../busybox-initramfs_1%3a1.27.2-2ubuntu3.1_amd64.deb ... Unpacking busybox-initramfs (1:1.27.2-2ubuntu3.1) over (1:1.27.2-2ubuntu3) ... Setting up systemd (237-3ubuntu10.15) ... Connection reset by 192.168.56.3 port 22 user@DESKTOP-FMS7LDB:~$ ssh user@192.168.56.3 ssh: connect to host 192.168.56.3 port 22: Resource temporarily unavailable