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frugal technology, simple living and guerrilla large-appliance repair
Mon, 10 Feb 2014

My Fedora 20 system dies for a day, but I find the culprit

This entry has been rewritten as How I fixed my Fedora 20 system when it stalled before the display manager appeared. I recommend reading that version.

Update: After booting into runlevel 3 (putting the number 3 into the GRUB boot line), I had no trouble logging into a console. Then I attempted to start X, and the system stalled. It was fglrx/Catalyst that was keeping me from getting to the display manager.

I removed AMD Catalyst. The system started working again. But back under the open-source Radeon driver, the laptop was running 20 to 50 degrees hotter than with the proprietary Catalyst driver.

Rather than reinstall Catalyst right away, I decided to try implementing Radeon DPM (Dynamic Power Management). DPM is a feature of Catalyst that is just coming to the open-source Radeon driver.

I'm running kernel 3.12.10, and Radeon DPM won't be implemented by default until 3.13. For now it has to be switched on with a kernel boot parameter.

The last time I tried forcing DPM in GRUB, I didn't get good results. This time it worked great.

I tested it by adding radeon.dpm=1 to the GRUB the boot line. The CPU temperatures and fan speeds were comparable to what they were under Catalyst (cooler and slower, respectively), and 3D hardware acceleration was working.

I did get something else from running Radeon instead of Catalyst: The screen dimming/brightening when running on battery power works (unlike with Catalyst). That means the screen dims when the laptop is not being used but brightens up when you start using it again. With Catalyst you had to manually increase brightness after returning to the machine.

So I modified GRUB to take radeon.dpm=1 permanently (instructions forthcoming).

The Linux gods give. And take. With Radeon (and not Catalyst) I lost suspend/resume. I'm not happy about it.

But having a working system again -- and having it without the bother of an unpackaged, closed-source Catalyst driver -- is a fair tradeoff. For now.

The original, before-I-fixed-it post starts below:

Ever since I got suspend/resume working in Fedora 20, I've been rebooting maybe once a week. That's because I love suspend/resume.

I love being able to close to laptop lid to put the machine to sleep and open the lid to wake it up.

But since the battery was running low last night, I decided to do a full shutdown.

I turned the laptop on today, and it wouldn't boot into Fedora proper.

I can boot into rescue mode, and all my files are there and look fine (that's the good news). But sometime during the boot process it just stalls. And there's nothing I can do to get it to finish booting and give me either a console or desktop.

Live images will boot. Windows 8 will boot. Rescue mode will boot. Just not Fedora itself.

I'm sure this has something to do with my use of suspend/resume and the fact that the Fedora installation is fully encrypted. The system does accept the passphrase and continues the boot after that. But the whole thing stalls pretty quickly -- and not always at the same part of the boot sequence.

Given enough sweat and throwing things at the wall, I could probably resurrect the system. The easiest thing to do might be a reinstall of Fedora with the same filesystem layout.

Tonight I'm going to do a final backup of my user files. And reinstall Linux.

But which Linux will I install? As I said, I could just go for Fedora 19 or 20 again. I could shift to Xubuntu. I might try Debian Jessie, but the init-system troubles ahead are giving me pause; I'd rather install with the new init system -- be it systemd (likely) or upstart (not likely) -- than have to upgrade to it along the way.

The more I think about it, I'll probably do the backup, then try for a Fedora 19 installation. That way I have a snowball's chance of getting my cheap HP USB printer working, there is still a packaged Catalyst driver, and it will be supported until a month after Fedora 21 is released, meaning I'm covered until at least September of this year.

But ... starting with the Xubuntu LTS right now would mean I could coast for up to five years without a reinstall if I wished. It's tempting.

Epilogue: If you're keeping score, I started today not being able to log in via the display manager. I ended by pulling Catalyst, invoking Radeon DPM, losing suspend/resume but otherwise getting performance close enough to Catalyst to stay with the less-troublesome Radeon driver for the time being.

And I don't have to nuke Fedora 20.