Several months ago I asked for assistance trying to upgrade from CentOS 7.9 to Rocky 9.4, while retaining the MATE window manager. The problem was that Rocky would only display via a VGA port to one of my two monitors and not through the HDMI ports (→DVI-D). Even after some helpful responses I could not make it work. So I left it as CentOS 7.9 largely satisfies my needs, but I have run into more issues, so I thought try again.
First of all, I splashed out on an ultrawide monitor in case there was a problem having the two screens. This worked out of the box with CentOS using HDMI→HDMI cables, just needing the original right monitor’s MATE panel to be deleted. Rocky 9 displays to the ultrawide monitor if I install it with GNOME, but a MATE installation will only display to the single VGA monitor. I hate the modern GNOME interface, so I’d welcome insights please on the reason for MATE’s different display behaviour, and hence a way to overcome it. I’ve tried with 9.4 and 9.6 with MATE Version 1.26.2. The latest ISO for 9.6 with XCFE too only displays via VGA. Is there a common denominator? Is there a boot option that needs to be added or changed?
Just before the login prompt appears on the small VGA monitor, Rocky and its logo appear briefly on the wide screen. My server has an NVIDIA GTX750 graphics card.
Thank you for thoughts and suggestions on this matter.
The Rocky team do not support upgrading from CentOS 7. The only supported upgrade was from CentOS 8 to Rocky 8.
Therefore, you should be making a clean install, ensuring you have a backup of your data. There are no other supported alternatives.
Also, Mate comes from EPEL repositories, so they are not even packages supported by Rocky either. Any problems with Mate not working, would need to be reported to EPEL.
If for example you install Rocky with Gnome and it’s working - maybe try adding EPEL at this point and install Mate and see if it works? All you need to do then is log out of Gnome Desktop, and change to Mate.
I personally use Rocky 9 and Cinnamon Desktop and works great on my 1920x1080 monitor.
Sorry if I confused matters in my broader usage of “upgrade”. My investigations involved clean installs from fresh ISO downloads of Rocky 9.4 and 9.6 with the various window managers, written to a new SSD separate from my CentOS 7 files. The MATE one also works via VGA on one of my old 1920x1200 monitors, but that real estate is too small for my requirements.
Thank you for clarifying that it’s an EPEL matter. The fact that I could download a Rocky 9 with MATE ISO misled me.
Classic Gnome works with the ultrawide monitor and is an improvement over GNOME 3 for me, but it’s far from ideal. So far I’ve not been able to make Dash to Panel work to make it more MATE like. Also I don’t see the gear at login to select the desktop, so had to edit /var/lib/AccountsService/users/ to override GNOME 3.
I’ll try your suggestion of adding EPEL, if it’s not already there,and installing MATE directly. If that is successful, the logout option may not work and I might need to edit the AccountsService configuration file again.
Yep, basically some of the ISO’s like Mate and KDE are built by the Rocky team, but using EPEL as a source of the packages to provide at least alternative desktops.
My thinking here is, if you install Rocky + Gnome and the desktops work, it could well be that a package is installed that may help with Mate. I realise it means having both Gnome and Mate installed and using extra space on your disk but if it works, then we know that we are missing some package that Gnome by default provides that is also required by Mate. If it doesn’t work even with both Gnome and Mate installed, then we know at this point that it’s a problem with Mate and that particular monitor/graphics card perhaps.
It’s not entirely clear from your post, but I get the impression that you have two monitors attached to your computer at the same time and Mate shows up only on the smaller one.
Have you tried connecting only the larger monitor and finding out if Mate will show up that way?
I also see mention of using a command called prime-select to set on-demand, which I guess is a nvidia-specific thing.
DVI-D is not HDMI. So which components have which connector? I use Mate exclusively on Fedora and Rocky. I don’t use Nvidia though, too troublesome. I do have a laptop that won’t connect over HDMI. It could be a cable quality issue that affects the Xorg driver that Mate uses vs the wayland that gnome uses. For the laptop I had to get a usb-c to displayport cable to get it to work with my monitor. Unfortunately there are a lot of factors here that may determine what works.
I’ll answer Frank and jbkt23d together. Apologies if my initial post was unclear, I didn’t wan to make it too verbose.
My 10-year-old server has two HDMI ports and one VGA. It was supplied with two monitors that I was using until recently. I wasn’t involved in the choice of its Nvidia graphics card.
When I began my many attempts to switch from CentOS 7 to Rocky 9, I did indeed have those two monitors, but my most recent tries were with a 5120x1440 ultrawide monitor. Being of a 2014 vintage, the two old monitors did not have HDMI ports, only VGA and DVI-D. So were connected from the server’s HDMI ports with HDMI-to-DVI-D cables (that was the meaning of my arrow, not that HDMI and DVI-D were the same).
The ultrawide monitor is connected via a brand new HDMI-to-HDMI cable supplied with the monitor, so is unlikely to be at fault. Also CentOS7 + MATE and Rocky 9 + GNOME 3 (including Classic) work fine on the ultrawide with that cable. So far Rocky 9 + MATE will not. display to it, Rocky 9 + MATE does display via the VGA cable to one of the old monitors, irrespective of whether I still have the ultrawide connected. It’s no surprise that the ultrawide doesn’t have a VGA port. There are other ports on the widescreen monitor, but it seems counterintuitive that a straight HDMI to HDMI would be inferior to HDMI to say DisplayPort.
I’m pleased to learn that Rocky 9 + MATE can work together, My next attempts tomorrow will try iwalker’s suggestion of installing MATE packages in a Classic Gnome session.
Rocky 9 comes with Nouveau driver for NVidia chips. The GTX 750 is a Maxwell generation chip, so it is still supported by current NVidia’s driver (not the “open” version though). Did you say whether you have installed NVidia’s driver, and if yes, which (as NVidia, ELRepo, and others do package that)?
Rocky 9 does also default to Wayland. Therefore, it offers both Wayland and X11-based Gnome sessions. (Until recently, NVidia’s drivers did disable Wayland.) Does Gnome “work” in both Wayland and X11 sessions?
If you run a session with X11, then what does the /var/log/Xorg.0.log show?
Does it say something about detected monitors?
Does it say differently in Gnome (HDMI ok) and MATE (no signal via HDMI) sessions?
Some DE – but I think it was Gnome – would store user’s preferences into user’s home dir, but if also the account is “fresh”, then there are no “old configs”.
Meaning that switching cables was not an obvious thing to try, given that the connection is via a new HDMI cable You are correct that I’ve not tried it, not least because I don’t have a HDMI-to-DP cable. I am open to buy one and try switching hardware if the software approach fails. I do want to move to Rocky 9 soon, and I’m game to try even counterintuitive (to me) ideas to achieve that goal.
Yes I’ve been running connected only to the new monitor most of the time. I just had an old one connected briefly as an experiment to see if Rocky 9 + MATE was installed correctly when no login prompt appeared on the new screen.,
I’ve not tried changing the driver this time around. In February I
did experiment installing a specific driver compatible with the GTX
750 (390 I think), but it didn’t solve my problem. I’ll need to
unearth the previous thread, where there were lots of helpful
information regarding Nvidia drivers and Wayland vs. X11.
One suggestion for the earlier thread to switch to X11 from Wayland
was to remove the comment character from
#WaylandEnable=false
in /etc/gdm/custom.conf. Today I tried that again and my new monitor
stays blank after a reboot. So I connected an old terminal via VGA and
the GNOME Classic desktop is visible there. If I restart gdm after that
edit, the screen goes blank, and a login prompt appears on the old
monitor, which gets me to a Classic session, but starting new windows
is slow with the X11 display server.
Earlier I installed a bunch of mate and related packages from EPEL,
and edited /var/lib/AccountsService/users/<username> to set
Xsession=mate. Upon rebooting, the Rocky logo appears on the
wide screen then disappears. Again if I connect the old monitor via
VGA, I can login, now to a MATE session.
Next I enabled Wayland, as I read that MATE 1.26 does have some
Wayland support—is it just some applications like the system monitor
and Atril that are supported? Now if I restart gdm, a login prompt
appears on the HDMI-connected wide monitor, but after entering my
password there, its screen goes blank. Again re-connecting the VGA
cable, the MATE session appears on the old monitor.
In summary whenever I choose MATE as my XSession or disable Wayland,
my session only appears via the VGA link.
I was looking in the bios on my lenovo laptop and noticed there is a setting under “Display” that allows more time for the video signal to be evaluated for external monitor connections. I don’t know if this is just for laptops or exists in other desktop MBs.