This would still be a flaky device or a kernel bug. Because the mentioned laptop-mode-tools version (1.71) brought in forced execution mode, so that it could apply proper power saving values. That's pretty much it. That does not result in read only rootfs because if it logically did, it'd be seen on every machine.
BTW, does Ubuntu have the systemd/udevd mount propagation fix included ? -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1726930 Title: System fails to start (boot) on battery due to read-only root file- system Status in laptop-mode-tools package in Ubuntu: Confirmed Status in systemd package in Ubuntu: Confirmed Status in systemd package in Debian: Fix Released Bug description: This report is to capture the extended diagnostic efforts done on IRC #ubuntu for user maszlo, who has a Lenovo T450 with SSD that was upgraded from 17.04 to 17.10 and since fails to complete start-up of services when powered on battery. We'd previously applied the "acpi=os=! 'acpi_osi=Windows 2015'" workaround in case this was an ACPI DSDT issue. This appears to be due to a read-only root file-system. What is not clear is how the rootfs goes read-only. The file-system (sda6, ext4) is fsck-ed successfully in the initrd according to the /run/initramfs/fsck.log. From the start-up logs (with "systemd.log_level=debug") we see the ext4 driver report a remount operation not once but five times. $ grep 'EXT4-fs.*sda6' systemd-debug.log Oct 23 18:10:44 T450s kernel: EXT4-fs (sda6): mounted filesystem with ordered data mode. Opts: (null) Oct 23 18:10:44 T450s kernel: EXT4-fs (sda6): re-mounted. Opts: errors=remount-ro Oct 23 18:10:46 T450s kernel: EXT4-fs (sda6): re-mounted. Opts: errors=remount-ro,data=ordered,commit=600 Oct 23 18:10:47 T450s kernel: EXT4-fs (sda6): re-mounted. Opts: errors=remount-ro,data=ordered,commit=600 Oct 23 18:10:48 T450s kernel: EXT4-fs (sda6): re-mounted. Opts: errors=remount-ro,data=ordered,commit=600 Oct 23 18:10:48 T450s kernel: EXT4-fs (sda6): re-mounted. Opts: errors=remount-ro,data=ordered,commit=600 Oct 23 18:10:49 T450s kernel: EXT4-fs (sda6): re-mounted. Opts: errors=remount-ro,data=ordered,commit=600 Those last five appear to be carrying options generated by laptop- mode-tools. User has disabled laptop-mode.service and laptop-mode.timer, and lmt- poll.service, but the issue remains. We see several reports of "read-only file-system": $ grep 'Read-only' systemd-debug.log Oct 23 18:10:46 T450s grub-common[1792]: grub-editenv: error: cannot open `/boot/grub/grubenv': Read-only file system. Oct 23 18:10:46 T450s systemd[1]: colord.service: Failed to run 'start' task: Read-only file system Oct 23 18:10:46 T450s gpu-manager[1797]: Warning: writing to /var/log/gpu-manager.log failed (Read-only file system) Oct 23 18:10:46 T450s systemd[1]: systemd-resolved.service: Failed to run 'start' task: Read-only file system Oct 23 18:10:46 T450s systemd[1]: systemd-resolved.service: Failed to run 'start' task: Read-only file system Oct 23 18:10:46 T450s gdm3[1932]: Failed to create LogDir /var/log/gdm3: Read-only file system ... Oct 23 18:11:26 T450s cupsd[1461]: Unable to change ownership of "/var/log/cups" - Read-only file system Oct 23 18:11:26 T450s cupsd[1461]: Unable to open log file "/var/log/cups/access_log" - Read-only file system Oct 23 18:12:52 T450s login[9248]: pam_lastlog(login:session): unable to open /var/log/lastlog: Read-only file system We also see several problems with systemd's connection to Dbus: $ grep 'Transport endpoint' systemd-debug.log Oct 23 18:10:46 T450s systemd[1]: Failed to send job change signal for 773: Transport endpoint is not connected Oct 23 18:10:46 T450s systemd[1]: systemd-logind.service: Failed to send unit change signal for systemd-logind.service: Transport endpoint is not connected Oct 23 18:10:46 T450s systemd[1]: Failed to send job remove signal for 156: Transport endpoint is not connected Oct 23 18:10:46 T450s systemd[1]: lmt-poll.service: Failed to send unit change signal for lmt-poll.service: Transport endpoint is not connected Oct 23 18:10:46 T450s systemd[1]: Failed to send job remove signal for 182: Transport endpoint is not connected Oct 23 18:10:46 T450s systemd[1]: Failed to send job remove signal for 95: Transport endpoint is not connected Oct 23 18:10:46 T450s systemd[1]: polkit.service: Failed to send unit change signal for polkit.service: Transport endpoint is not connected Oct 23 18:10:46 T450s systemd[1]: cups-browsed.service: Failed to send unit change signal for cups-browsed.service: Transport endpoint is not connected Oct 23 18:10:46 T450s systemd[1]: Failed to send job change signal for 773: Transport endpoint is not connected Oct 23 18:10:46 T450s systemd[1]: Failed to send job remove signal for 161: Transport endpoint is not connected Oct 23 18:10:46 T450s systemd[1]: gdomap.service: Failed to send unit change signal for gdomap.service: Transport endpoint is not connected When the user purged laptop-mode-tools the system starts successfully on battery. The user installed a fresh instance of 17.10 on a 2nd M2 SSD. When laptop-mode-tools was added to that instance it also exhibited the failure. # apt-cache rdepends laptop-mode-tools laptop-mode-tools Reverse Depends: systemd tlp powertop-1.13 powertop # apt show systemd | grep Breaks Breaks: apparmor (<< 2.9.2-1), ifupdown (<< 0.8.5~), laptop-mode-tools (<< 1.68~), systemd-shim (<< 10-3~), udev (<< 228-5) # apt-cache policy laptop-mode-tools laptop-mode-tools: Installed: (none) Candidate: 1.71-2ubuntu1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/laptop-mode-tools/+bug/1726930/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp