After sending the original report, I reverted to using the older 5.4.0-136-generic kernel. That was a week ago, and there have been no freezes while using the older kernel. This confirms that the freezes are indeed specific to the 5.4.0-137-generic kernel.
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-signed-hwe-5.4 in Ubuntu. https://bugs.launchpad.net/bugs/2006807 Title: Ubuntu freezes and disk inaccessible until next boot Status in linux-signed-hwe-5.4 package in Ubuntu: New Bug description: About once every two days since I updated to the 5.4.0-137-generic kernel, ubuntu has partially frozen. This has happened three times so far. In every case the freeze occurred when I tried to save the file that I had been working on for a while in emacs. The first indication of trouble was that the cursor disappeared within the emacs window. When I moved the cursor out of the window the cursor reappeared, but then it disappeared again when I moved it back into the emacs window. However even outside the window, nothing responded to mouse presses, although youtube audio continued to play from firefox. The last time this happened, I was also running htop in one of the virtual console terminals (VT3), and also a process that queried the CPU temperature every second in another (VT4). When the desktop froze, I was able to switch VT's and see that these were still running. However switching back to the GUI VT brought up nothing but a black screen and a flashing cursor. The htop process in VT-3 showed many system processes were still running in the background, and there was plenty of free memory. In the VT running my temperature monitor, I used Ctrl-C to get to the shell prompt. However bash couldn't find any executables, so I couldn't run ls, df or anything else except bash's builtin commands. I concluded that my laptop's disk had probably gone offline. Since I couldn't run anything from the VT shell prompt, I tried using htop to send a TERM signal to udiskd, naively hoping this might cause it to restart and wake up the disk. However this crashed htop, and resulted in a message from systemd saying that it was freezing execution. At that point I used SysRq REISUB to reboot the laptop. However the boot failed with a splash screen saying that there was no disk to boot from. I ended up having to long-press the power button before it would see the disk again and boot normally. My guess is that the internal hard disk (Micron 2200S NVMe 256GB) went into a low-power state during an interval when I wasn't writing anything to disk, and then it failed to wake up. To verify that the offending disk doesn't have any problems, I have since used the nvme command to check the disk's smart log and error log. No errors had been recorded, and it still has available_spare at 100%, so it appears to be healthy. For the moment I am going to switch back into the 136 kernel for a few days (or until it freezes), to confirm whether the freezes are kernel related. If that doesn't work, I will try disabling apst power- management at boot time. In the meantime, I'd be interested to hear any suggestions anyone has for diagnosing and resolving this problem. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-5.4.0-137-generic 5.4.0-137.154~18.04.1 ProcVersionSignature: Ubuntu 5.4.0-137.154~18.04.1-generic 5.4.218 Uname: Linux 5.4.0-137-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.28 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Fri Feb 10 12:05:02 2023 DistributionChannelDescriptor: # This is the distribution channel descriptor for the OEM CDs # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor canonical-oem-somerville-bionic-amd64-20180608-47+italia-whl+X37 InstallationDate: Installed on 2019-08-22 (1267 days ago) InstallationMedia: Ubuntu 18.04 "Bionic" - Build amd64 LIVE Binary 20180608-09:38 SourcePackage: linux-signed-hwe-5.4 UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe-5.4/+bug/2006807/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
