Fedora 29 mini-review on Talos II

Although I don't think anyone has good data on this so far, I suspect that Fedora usage among Talos II users is pretty high because it was among the first to offer POWER9 support out of the box. I believe Debian has the greatest install base overall because of its general reputation and it seems to be the one Raptor recommends, but I still wager that Fedora is in the top couple. Indeed, coming from the Power Mac world without loyalties to any particular distribution, the fact I could just throw a bootable Fedora CD into my brand-spanking-new T2 and install an OS without any fuss was pretty much the whole reason I'm using Fedora now. Fortunately, after an initially bumpy start with some weird glitches here and there, F28 Workstation has generally been a very pleasant experience and I think most distros that support Talos systems are now to that point. This review, then, is not a general review of Fedora 29, but rather a review of F29 from the perspective of a Talos II user and anything relevant to this platform that I encountered.

If you are unfamiliar with Fedora, the most important thing to remember is that there is no such thing as a Fedora LTS (if you want that kind of extended support, then you really should be using CentOS or Red Hat Enterprise Linux). Releases are maintained on an N+2 system: now that Fedora 29 is out, F28 will be supported until one month after F30 is released and F27 will be shortly unsupported since we are roughly a month after F29 emerged. In practice this means any one release is supported for roughly a year, give or take, so it really is important to stay current with official releases. On the other hand, since the cadence is somewhat quick, the chance of major breaking changes between any two consecutive releases is relatively low.

A few notes about my configuration before we begin. My high security systems are on a standalone wired network that cannot route directly to the Internet, only through proxies, and this system has the BTO AMD WX7100 workstation card as its primary console with the VGA port jumpered off. It comes up with a textual boot (not graphical) so I can do updates with high confidence of not interfering with anything running; I manually do a startx when I want to start GNOME from there. (Incidentally, I didn't like the default icky PC VGA font, so I changed it to the Sun workstation font shown in the photograph which I think befits this machine better. Just set FONT="sun12x22" in /etc/vconsole.conf.)

If you don't have your GPU's firmware loaded in to Petitboot, you may wish to consider doing so before upgrading to or installing F29. If this is not possible or feasible, you may find life a bit easier if you use the VGA port (make sure it is not jumpered off), particularly if you are installing from scratch. In my case, I don't have the firmware on the Petitboot side yet since I rarely work with Petitboot directly, but I did need to have the VGA jumpered back on to actually install Fedora for the first time. For the upgrade this is optional but requires a few more steps. I'll talk about this in a moment for the benefit of those with unusual video cards or issues with them during early IPL.

Rather than upgrade immediately when F29 was available, I waited a few weeks to ensure that updated packages were available from both Fedora and the RPMFusion repositories. When I was ready to upgrade from F28 to F29, I quit GNOME and returned to the text console, and started the upgrade process with the standard steps:

sudo dnf upgrade --refresh # upgrade DNF
sudo dnf install dnf-plugin-system-upgrade # install upgrade plugin
sudo dnf system-upgrade download --refresh --releasever=29 # download F29 packages
sudo dnf system-upgrade reboot # reboot into upgrader

(GNOME Software can apparently do this for you automatically, but I prefer to kick off such updates manually. If you are installing F29 from scratch, however, install from the ISO for the Server or Everything versions as usual for ppc64le and then convert to Workstation afterwards if desired.)

If you have the firmware loaded in Petitboot or you are using the VGA, you can see the upgrade progress automatically begin after the system reboots. If you don't, however, you can still monitor the system by pressing CTRL-ALT-F2 for an alternate console, logging in as root (other UIDs are locked out) and periodically issuing

dnf system-upgrade log --number=-1

which displays the log so far. You'll see the normal dnf strings you would ordinarily do as it goes through the packages.

On my system the upgrade process (after the reboot) took about an hour and I went to bed in the middle of it. I woke up a few hours later to find the Talos at a black screen with its fans roaring at top volume, which looked like it had gone berserk during IPL when the upgrade ended with an automatic reboot. This caused a few nervous moments when I had to hard-power it off from the front power button and bring it back up. Fortunately, the machine then booted immediately into F29 and the system upgrade log showed that dnf had completed the upgrade without any errors. All of the packages I currently use seem to have made it over, so pretty much anything else you need to have on ppc64le should "just work" at this stage.

There are many small improvements in F29 but the two big ones are Fedora Modularity, allowing shipping multiple package versions on the same platform base, and GNOME 3.30. Although this problem is not specific to the Talos, the GNOME upgrade introduces issues of its own:

One minor annoyance was that the system monitor extension I use had gone a little nuts and needed to be reconfigured. However, the big annoyance is that as you can see from the screenshot Epiphany (GNOME Web) no longer supports plugins, including the one to manage GNOME extensions. The Tweaks window demonstrates I use quite a few of them, so losing that feature really hurts their management -- especially because trying to install and use the Firefox extension instead still gives up with an error about a missing "native host connector" even after I installed and manually confirmed the native host component was present. The big one was that Dash to Dock needed an upgrade and installing GNOME extensions by hand isn't exactly an entertaining pastime.

The trick is that the Fedora package for the native host connector only includes the JSON native messaging descriptor for Chrome. Since we don't/won't use Chrome and there isn't an official release for POWER9 anyway, we have to create our own: once you have downloaded and installed the Fedora native host connector package and the GNOME shell extension for Firefox, place the contents of this gist into ~/.mozilla/native-messaging-hosts/org.gnome.chrome_gnome_shell.json and restart Firefox. Now, when you visit the GNOME Extensions site, it should simply "just work" and the browser should now be able to automatically enumerate, install, disable, enable and upgrade your GNOME extensions.

On the whole, a week into the installation, I don't notice a great deal else, which means the upgrade was relatively uneventful overall (the most desired attribute of any system update). One thing I do notice is that running updates is now quite a bit faster (downloading a lot less metadata) and this is very welcome. Bumps are unfortunately to be expected and we should be striving for better in Linux if we want to be a viable alternative to macOS and Windows, but I'm relieved to say that at least with this update, the update wasn't much bumpier on our unusual black beast.