Fedora 15 versus me

October 22, 2011

To perhaps the relief of some people, I am no longer running Fedora 8 on my home machine; I've now pretty much finished migrating to Fedora 15 on my new hardware. I did the actual migration the way I'd planned; I installed Fedora 15 from scratch on the new machine's system disks, transplanted the old machine's mirrored disks into the new machine as additional data disks, and then mounted my home directory filesystem and so on.

(It's bit annoying that Fedora 16 is so close to release, since I'm just going to get to upgrade my machine in a month or so. I did consider installing a Fedora 16 Beta instead of Fedora 15, but in the end I decided that I didn't want to take the risk of problems during a Beta to release upgrade. And, you know, it's a beta.)

That 'and so on' handwaves a lot. The tedious and time consuming portions of this migration were reconfiguring the more or less stock Fedora 15 install to work in my peculiar ways and updating my usual environment to work on Fedora 15. The latter was vastly helped by the fact that Fedora 15 is quite close to Fedora 14 (as far as my environment is concerned), which I'm running at work, so I could simply copy a lot of stuff from my work setup.

In the process of doing all of this I have some random notes:

  • if pressed, I can actually work in Gnome 3 and get things done. It's merely annoying (but not sufficiently annoying to get me to set up XFCE for strictly temporary usage).
  • Gnome 3 really doesn't expect you to have more than a small handful of local users. The gdm login widget really doesn't like it (and in Gnome 3.0, excluding users from being shown in the login window is apparently an unimplemented feature).

  • I gave SELinux a try, I really did, but in the end I once again turned it off at about the time I couldn't start X as myself because something in my home directory had the wrong SELinux permissions (or no SELinux permissions, since I've run Fedora 8 for years with it turned off). I'm sure that I could have fixed all of the issues with enough work, but it just wasn't worth it and I was in a hurry.

  • since Fedora 15 has migrated to Gnome 3, the standard Gnome 2 volume control applet has vanished. I didn't find an alternate volume control applet that I liked; in the end I just copied the Fedora 14 binary from my work machine and fortunately it worked.

    (This is one of the drawbacks of Gnome 3; alternate environments can no longer use Gnome 3 widgets, because they're very tightly tied to the Gnome 3 shell.)

  • I'd like to say that while I wasn't looking Liferea turned from a nice little feed reader into a buggy crash-prone monster, but that's not really true. First, I had advance warning from things that Pete Zaitcev had written, and second if I'm being honest I always patched Liferea a bit myself and did other peculiar things (like running a 1.2 version well after it became obsolete even in Fedora 8).

    Update: I unfairly maligned Liferea here; it turns out the crashes weren't its fault.

  • I have acquired a grim hate of NetworkManager, or at least of trying to mix NM with any by-hand network configuration. As it happens my home machine needs a lot of by-hand network setup, so in the end I had to turn NM off entirely. I'm happy to report that this is not too difficult to do with systemd.

    (The bit that drove me over the edge was how when NM was running but not managing my DSL link, applications like Firefox and Liferea started up thinking that the system was offline. I can see the chain of logic that gets the system to that point, but it's wrong.)

I don't want to say anything about systemd right now, because it's new to me and I just haven't had the time to look into it and get familiar with it. My current off the cuff reactions are from a position of ignorance.

Okay, I'll say one thing: even allowing for better hardware than my old machine, it feels like my new machine boots startlingly fast (although I think that part of this is the wall of text that flows past in a text mode boot).

  • it feels kind of liberating to know that I've thrown out a lot of random strange customizations in the move, since I installed Fedora 15 from scratch (on the new system drives). I've copied some customizations from the old system filesystems in order to get things the way I want them, but it's a much more minimal set than I used to have.

    (If I'd had lots of spare time to do the migration I would have kept careful notes and then set up Puppet or Chef to apply all of my customizations automatically, but not this time.)

  • I've taken the advice made in comments here and simplified my clutter of system filesystems down to /boot, swap, and /, with /usr and /var rolled into the root filesystem. It's really not worth being more picky any more and it's nice not to have to worry about one piece running out of space when there's lots left elsewhere (and I made the root filesystem 100 GB just to really overkill the issue).

    (Unfortunately I didn't think to make / be LVM on top of RAID-1, which would have let me use LVM snapshots.)

    (My jumble of user filesystems continues unabated, since I'm using them as-is; I literally just brought up the software RAID arrays, activated LVM, and started adding things to /etc/fstab.)

I have some things to say about the experience of having a new, modern machine, but that's a subject for another entry; this one is already long and rambling enough.


Comments on this page:

From 109.78.65.253 at 2011-10-22 19:32:38:

Sounds like you didn't have it too bad given the jump. Here are my notes in case it's useful: http://www.pixelbeat.org/docs/f15.html

Note I'm testing F16 lately and it's quite good (and no btrfs unlike I mentioned in the above article). This is a good bootstrap for F16 (2 days old): http://dl.fedoraproject.org/pub/alt/stage/16.TC2/Live/x86_64/

From 71.228.115.45 at 2011-10-29 16:23:00:

Actually I had no issues with crashing in Liferea ever since they fixed the Java applet problem. However, the performance is awful, and I do mean it: awful. The switch to sqlite ruined everything. What's interesting, Firefox made the switch at about the same time, and hit a lot of performance issues, in particular around Awesome Bar, but they very much managed to fix their problems. It clearly shows that sqlite can be made to behave, although perhaps only if you can throw resources of Mozilla Foundation at it. Lars very much screwed the pooch here.

From 87.79.236.202 at 2011-10-29 21:20:52:

I feel I have to take some responsibility for that one because I was the one who egged Lars on to switch to SQLite.

And SQLite is not the problem.

Only recently did I finally watch what Liferea really does, and… err… let’s just say it doesn’t use SQLite the way you should. If you have folders showing the contents of all of their contained feeds, you can easily get Liferea to load tens or hundreds of thousands of headlines, one by one with separate SELECTs, followed by C code examining each of them individually to decide which ones to display and which not.

If that’s how the code was going to be written then Liferea should have used BerkeleyDB…

Now I’m wondering if it’s worth bothering to undertake the huge refactor that will be required to get Liferea to use SELECTs that return more than one row each, and which use conditions so the set of headlines will be reduced to the ones that will be loaded at the database level already, and all the C code has to do is shovel them into the ListStore. If that much. I believe it would not be too complicated to write custom TreeModel that interfaces to an SQLite result set directly, which would avoid lots of redundant data copying. — As you see, there is plenty of… untapped optimisation potential.

It’s not SQLite that is to blame here. Really it isn’t. It’s apps that use SQLite but not entrusting it with its actual job (which it does very well), i.e. getting the right set of data out of the data store, and quickly.

(The other option dangling seductively in front of me is to write something from scratch for my own needs and ditch Liferea.)

Aristotle Pagaltzis

By cks at 2011-10-30 01:48:53:

The information about liferea is interesting, because I've had the reverse experience; liferea crashes (except when I want it to) but when it doesn't crash it performs fine. I'm not sure why this is; possibly I am simply throwing enough memory at it (directly and indirectly in filesystem buffers) so that SQLite performs well anyways. Or perhaps my usage is different than Pete Zaitcev's.

(If anything, the SQLite version of liferea sometimes performs better than the old 1.2 its-own-database version. I have thousands of unread feed entries and it used to be that if I accidentally selected the 'Unread' pseudo-folder, liferea would immediately hang for a minute or so before it noticed my frantic attempt to select another folder. In the 1.8 release candidate, selecting the 'Unread' pseudo-folder causes only a brief pause and things are completely responsive.)

By cks at 2011-11-19 01:51:45:

On the crashes: it turns out that they weren't Liferea's fault but were instead because I had a https feed or two and there's some bugs in glib-networking's TLS support. See LifereaCrashUpdate.

Written on 22 October 2011.
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