Public bug reported: I've had this happen twice on kernel upgrades, most recently when linux- image-extra-4.4.0-95-generic failed to download due to an iffy connection. Because linux-image-4.4.0-95-generic did successfully download, its setup (run-parts: executing /etc/kernel/postinst.d/zz- update-grub 4.4.0-95-generic /boot/vmlinuz-4.4.0-95-generic) was run and an initrd file built.
The problem is that the resulting initrd file is less than half the size it should be, lacking all of the drivers that would have come in from the "extra" package: -rw-r--r-- 1 root root 38288353 Aug 22 10:09 initrd.img-4.4.0-89-generic -rw-r--r-- 1 root root 38289328 Aug 22 10:11 initrd.img-4.4.0-93-generic -rw-r--r-- 1 root root 38371214 Sep 2 06:00 initrd.img-4.4.0-94-generic -rw-r--r-- 1 root root 16899714 Sep 11 12:15 initrd.img-4.4.0-95-generic The result is a system that upon reboot cannot access important things such as the network. Recovery involves putting hands on the console and using GRUB to manually select a prior kernel with a good initrd. Recommendation: Do not allow the build of initrd and consequent activation of the new kernel as default without making sure the extra package has been or can be installed if selected. At the very minimum, issue a warning that the system may not be properly rebootable. Note that the following information is compiled while booted from kernel 94 rather than the kernel 95 with the faulty initrd. # uname -a Linux xena 4.4.0-94-generic #117-Ubuntu SMP Tue Aug 29 08:13:56 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux # cat /proc/version_signature Ubuntu 4.4.0-94.117-generic 4.4.83 # cat /etc/os-release NAME="Ubuntu" VERSION="16.04.3 LTS (Xenial Xerus)" ID=ubuntu ID_LIKE=debian PRETTY_NAME="Ubuntu 16.04.3 LTS" VERSION_ID="16.04" HOME_URL="http://www.ubuntu.com/"; SUPPORT_URL="http://help.ubuntu.com/"; BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"; VERSION_CODENAME=xenial UBUNTU_CODENAME=xenial --- ApportVersion: 2.20.1-0ubuntu2.10 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: mikebw 2674 F.... pulseaudio /dev/snd/controlC1: mikebw 2674 F.... pulseaudio DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2014-01-21 (1329 days ago) InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1) MachineType: System manufacturer System Product Name Package: linux (not installed) ProcEnviron: LANGUAGE=en_US TERM=xterm-256color PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 radeondrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-94-generic root=UUID=8f5d219a-699a-42fc-a668-7c78fbab134a ro quiet splash usbcore.autosuspend=-1 vt.handoff=7 ProcVersionSignature: Ubuntu 4.4.0-94.117-generic 4.4.83 PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. RelatedPackageVersions: linux-restricted-modules-4.4.0-94-generic N/A linux-backports-modules-4.4.0-94-generic N/A linux-firmware 1.157.12 Tags: xenial Uname: Linux 4.4.0-94-generic x86_64 UpgradeStatus: Upgraded to xenial on 2017-07-29 (43 days ago) UserGroups: _MarkForUpload: True dmi.bios.date: 08/13/2010 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 2104 dmi.board.asset.tag: To Be Filled By O.E.M. dmi.board.name: M4A785TD-M EVO dmi.board.vendor: ASUSTeK Computer INC. dmi.board.version: Rev X.0x dmi.chassis.asset.tag: Asset-1234567890 dmi.chassis.type: 3 dmi.chassis.vendor: Chassis Manufacture dmi.chassis.version: Chassis Version dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr2104:bd08/13/2010:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnM4A785TD-MEVO:rvrRevX.0x:cvnChassisManufacture:ct3:cvrChassisVersion: dmi.product.name: System Product Name dmi.product.version: System Version dmi.sys.vendor: System manufacturer ** Affects: linux (Ubuntu) Importance: Undecided Status: Confirmed ** Changed in: linux (Ubuntu) Status: New => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1716457 Title: Failure to download linux-image-extra-*-generic causes initrd to be built incorrectly with no warning To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1716457/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs