Once most of the features that were planned for SUSE 15 SP2 and openSUSE 15.2 are ready, the team is shifting its focus to SP3 and 15.3. Of course, we are still polishing the releases around the corner, so in the summary of this sprint, you can find a mixture of bug fixes, small features, and preparation for the future work. These topics are:
- NCurses installation in old graphic chips
- Booting from Remote Encrypted devices
- Smarter network configuration in Linuxrc with the new
- Better support for auto-configured devices in S/390 systems
- Researching about how to improve XML YaST’s parser
Coming Back to Haunt Us: NCurses Installation and Old Graphics Chips
Some months ago (for Leap 15.1 / SLE-15 SP1), we started using fbiterm for all NCurses (text-based) installations. We had always used it for certain languages like Chinese, Japanese, Korean that need special support for their fonts, but since there were font-related problems even for other languages, we are now using it in all cases.
This fixed those font-related problems, but it turns out it brought back another issue that seemed long forgotten: poor performance in text mode for specific graphics chips.
Remember the Matrox G200? It was a good choice for Linux systems back years ago. Back many years ago; that GPU had its 20th anniversary in 2018, so it dates back to 1998 (that was when Windows 98 was new). Its graphics performance was… let’s call it quite okay for a budget card even back then.
Well, it turned out that it is still used today by some rack server manufacturers as on-board graphics. Most on-board graphics these days uses Intel GPUs (and they work great), but not all: some indeed use that old Matrox G200.
We had a business customer inquiring why screen redraws while installing their rack servers were so slow with SLE-15 SP1 compared to SLE-15 GA, and that’s the explanation: Those machines have that Matrox G200 on-board graphics, and it doesn’t seem to have the hardware acceleration that would be good to have for a framebuffer console. And with fbiterm you can now really see the difference.
In that setup, you can observe the NCurses library at work in slow motion: You can see how it partially removes text from the cursor position to the end of the line (leaving part of the screen black) and then redraws content from there. It’s not wrong or buggy, it’s just slow. Unbearably slow, like back then having a very slow (4800 baud) terminal connection (remember those?).
So our recommendation for that kind of hardware is: Better not use a framebuffer console. Just leave the machine in plain text mode with 80x25 with the nomodeset boot parameter, or do an SSH installation.
Those old ghosts keep coming back to haunt us, even from back in the very late MS-DOS days.
Improve Booting from Remote Encrypted Devices
But not all ghosts are that old. We also got the visit of the spirit of the past sprints. In one of
our November posts, we explained
how we had addressed the existing problems booting from remote encrypted devices by adding the
_netdev option to the
crypttab files for all network-based file systems.
For some months, it looked like the definitive solution. But recently it was reported that, as much as that option indeed pleases systemd, it confuses dracut when it is used in the root file system. Although they say you cannot make everybody happy, we found that adding that option to all file systems except the root one actually seems to be the right solution for both systemd and dracut. The latter does not get confused anymore and turns out the root file system is the only one for which omitting the option is safe for systemd.
With all that, SLE-15-SP2 (and Leap 15.2) should exhibit a pretty solid behavior for all scenarios involving installation on top network disks, encrypted or not. For more technical details, you can check the corresponding pull request.
Let’s try ifcfg in Linuxrc
Linuxrc is a piece of software responsible for booting the installation media. It offers a friendly interface to set up some basic stuff (e.g., the language) and takes care of initializing the hardware and preparing all the stuff that YaST needs to do its magic.
Alternatively to the good looking interface, it provides a really powerful command line too. If you have not done it before, we recommend you to check the Linuxrc wiki page.
One of the things you can set up using the command line is the network, which is really handy when you want to do an installation from a network source.
With these settings, Linuxrc configures the first device that matches the
eth*. But what happens
if you have multiple network interfaces? Is the configured interface the right one to reach the
To deal with these situations, we have added a
try feature to the
In this case, Linuxrc tries to find the device which matches the pattern and makes the installation source reachable.
try keyword works for static configurations as well as for DHCP. When used with DHCP the
difference is that the DHCP setup is done for just one device. Without the
try keyword, the DHCP
configuration is assigned to all devices which match the device pattern. So, if you use:
you’ll end up with one DHCP configured device (the one that has a working network connection). On
the contrary, omitting the
try option will configure via DHCP all the devices matching the given
You can use any of Linuxrc’s network-aware options as criteria for the
try option (
autoyast). However, you cannot explicitly determine which one will be used if
more than one is given. It merely depends on which one is used first by Linuxrc.
Better Support for Auto-Configured Devices in S/390 Systems
A few weeks ago, we announced that we had extended Linuxrc and YaST to play nicely with the new I/O device auto-configuration mechanism on zSeries systems. After gathering some feedback from our S/390 experts, we did some adjustments to the current implementation.
On the one hand, the auto-configuration is now optional. Linuxrc offers a new
that allows the user to indicate whether to apply the configuration. The possible values are
1 (yes) and
2 (ask). The last of those values is the default.
On the other hand, QA detected a problem when AutoYaST tried to configure a device that has been already configured. Apart from solving the issue, we invested some time doing cleaning-up part of the yast2-s390 module.
Improving YaST’s XML Parser
XML is an important language in the YaST world. The best example is the so-called control file, which defines many aspects of the installation process. You can check the control file for openSUSE if you are interested.
YaST implements its own XML parser which is adapted to our needs. For instance, it is able to
understand an special
config:type attribute which serves as a hint about to interpret the content
of the XML tag. If you have used AutoYaST, you know what we are talking about.
However, it has its own set of problems, especially when it comes to error reporting. For that reason, we have started a new initiative to improve our XML parser. There are some discussions which are taking place in the yast-devel mailing list (like YaST XML Parser and Yast XML parser and strictness). Feel free to join and share your point of view.
To plan for the future, the team has started to do some research about the current status of YaST modules and AutoYaST. You might already have read something about them if you are subscribed to the yast-devel mailing list. If you want to share your point of view, you are welcome to the discussion.
In any case, we plan to present our conclusions during the upcoming weeks. So stay safe and tunned!