It may be harmless but seeing that in GRUB bootloader makes me uneasy. 
Now, my emotional mind is telling me to try install Debian once more but my practical mind asking me how could I solve that iommu problem?
That means in this case I don’t have to enable the iommu in BIOS, right?
BTW, why this person named SOURAV changing the category of this thread to ‘OTHER DISTRIBUTIONS’ instead of ‘DISCUSSION’ ???!!! I don’t understand!!!
Not sure, I think you may have to enable iommu in BIOS if you use it in any way.
Disable os-prober in /etc/default/grub
# If your computer has multiple operating systems installed, then you
# probably want to run os-prober. However, if your computer is a host
# for guest OSes installed via LVM or raw disk devices, running
# os-prober can cause damage to those guest OSes as it mounts
# filesystems to look for things.
# OS_PROBER re-enabled by Debian Calamares installation:
GRUB_DISABLE_OS_PROBER=true
I’d keep it disabled, and try to boot with iommu=off then iommu=soft and see how behaves so.
Sourav is the moderator.
He likes to keep topic names and categories informative.
It really is Fedora specific, so I think Sourav is correct here.
Ok. Then I will make a persistence Live USB so that all changes made to system, will be saved.
Oh! I didn’t know. Sorry.
Why make it more complicated?
Just boot the way I showed.
To try whether it works OK so, it’s good enough, and done in seconds…
Then when it doesn’t work as expected, it’s possible to try different setting the same way - very easily.
And when it works OK, just apply the bootup parameter to the installed system afterwards - much easier, than to fiddle with a persistent live.
That is an update to a new release number.
How did you do that in Fedora?
I hope you did not do a fresh install of the new release without erasing the old release? … that would make a mess.
If you really did the upgrade to a new release with a proper inline upgrade, we have to conclude
Either way, you now have a messed up grub setup.
You may be able to correct it by booting Fedora and doing
update-grub
Otherwise, wipe the lot and do a fresh install.
Like I said before, Fedora is not an easy distro for beginners.
I had Fedora 40 installed. When I saw the system upgrade package for Fedora 41 is more than 3gb, I decided to do a fresh install. I took backup. I installed Gparted in the Live USB and then wiped the drive clean and partitioned it into two with ext4 filesystem. Then in one partition, I installed Fedora 41. Later I formatted the 2nd partition with exFAT when automount failed.
If I have to do a fresh install, then I will try Debian one more time.
You don’t need to install to try.
That’s the purpose of the live.
Just boot the live with the “iommu” options.
If it does not work, you tried…
If it works, you can install, and start to use it.
It sounds like you did everything correctly.
I cant explain it?
@kovacslt László, I am answering to this post of yours: Cinelerra-gg AppImage doesn't show my mounted drives - #16 by kovacslt.
I tried to test the Debian 12 live USB again. This time I connected the USB to the USB 3 port and it showed the initial menu as your picture. Then I did exactly what you have advised, with both iommu=soft and iommu=off and both of them… didn’t work.
So, Debian 12 is still doing this weird thing. In Debian’s own forum, someone complained that Debian 12 is not recognising his USB drives but Debian 11 was able to detect it properly. Now I used dmesg and got the following result:
Do you have any devices other than KB and mouse connected to USB… if so try removing them.
Try nohz=off kernel parameter
Also try (not together and not with with above)
Also try installing the library libusb-0.1.so.4
It is missing in the Debian 12 .iso.
Reboot after installing it.
Last resort, try Debian 11 (why… the Debian 12 iso may have other things missing)
Nev and László, can you please give me the exact link to download Debian 11 full ISO DVD which will not require internet? I tried hard to find it at Debian’s website but I could not find the exact DVD image. All download links are pointing to version 12 ISOs. The last version of Debian 11 was Erata i.e. Debian 11.11.
Update: I got the link and have downloaded the ISO. What I did wrong with the non-free firmware ISO is that I missed the words net-install. That’s why it always tried to connect to the net and due to USB 2 port detection problem, it could not connect to the internet.
@nevj, @kovacslt, @daniel.m.tripp Debian didn’t work for me… sorry friends. With iommu=soft, iommu=off, nohz=off and pci=noats didn’t create any effect on the system. Only iommu=pt showed its effect on the system and it gave me sweat. See the picture below:
When I pressed the Ctrl+Alt+Del, the above errors started rolling continuosly and Ctrk+Alt+Del didn’t work anymore and I had to hard reset my pc. It was really a horror show. 
Same thing for Debian 11, omly exception was I didn’t use the iommu=pt this time. Its effect was scary… really.
So it seems that Debian does not like my system.
Did you try the library?
try installing the library libusb-0.1.so.4
It is probably there in Debian 11 anyway.
That is strange… I can not imagine Fedora having anything that Debian does not have.
Fedora may be more bleeding edge, but that should not matter for your machine.
Does a Debian live iso run?
I have not installed Debian. I experimented with the live ISO.
If the live iso does not work, you are stuck. They are generally better configured than an install to deal with hardware .
How many distros have you tried? I would try some of the major Debian derivatives, like Devuan, MX, Ubuntu, LMDE. It is easy enough to try a live iso.
I have tried MX, Rocky, Pop, Peppermint, Mint, Mint LMDE - all live ISOs.
Pop - Display problem with Nvidia and after that I haven’t tried because I don’t like its getup.
Rest of the OS, all gave USB 2 port error. As Mint (not LMDE) based on Ubuntu and could not access USB 2 ports, I think Ubuntu would also give the same error. But even if it (Ubuntu) works error free, I will not go for it. Why? Because of two reasons. First, I don’t like the look of Ubuntu and the second reason which is the most important one, is they were awarded the Austrian anti-privacy Big Brother Award for sending local Ubuntu Unity Dash searches to Canonical servers by default and this is the reason for which I don’t trust any Ubuntu based distro and I was keen to use Debian in the first place. I don’t know whether Fedora does it or not but it is also funded by a corporation. I will search internet for any such news.
Though I don’t know for certain why all other distros behaved in the same manner as Debian but I think it might happen that my USB 2 ports have become weak. Windows might have no such strict rule for checking adequate power supply to those ports as Debian has and as Debian is the father of all distros, every Linux distro might has some codes from Debian. Thus they are also failing to access the USB 2 ports in my motherboard. I tested Debian live on my wife’s PC which has a B450M-DS3H-WIFI motherboard and it didn’t give any problem as that motherboard doesn’t have any USB 2 ports. Nowadays Linux really meant for latest hardware which is very disappointing. 
If you are right, you may be able to get around it by plugging a powered usb hub into one usb2 port.
The only major distros independent of Debian are Fedora, Solus, Void, Arch and Arch derivatives, Gentoo. Of those you have only tried Fedora. The easiest one of those to try is Solus.
This is really a very good idea to test the problem. Thank you.
I will try this.
Update: I was searching for some info on the background of Solus, like who are the developers (not that I know them by person 
), the origin, their motto, some info on the development and maintenance … I mean the normal stuffs which I always look for before using any software, specially OS i.e. Linux because if on the midway the developers would think to leave the project for good then it will become a big headache. Plus hardware requirements and support and I was very surprised to see that they support really old hardware specially GPUs like ATI R300 which was released in 2002!!! So, probably it will support my motherboard. But as an organisation, I found some disheartening and alarming news. Read it here: Solus Linux Co-Lead Resigns, Joins Serpent OS and Plans to Fork Budgie Under a New Organization. Even the creator of Solus, Ikey Doherty has also resigned in 2018. So, in my opinion, if the creator leaves his own ongoing project, it is not a good indication. Anyway, let’s see.
