Kubuntu 21.04 fails to install

[gh4wi]

Updated Post for Kubuntu 21.04 install fails when booted via DVD.

Downloaded Kubuntu 21.04 and successfully created DVD using Brasero in the usual manner.
Booted DVD on PC which normally runs Kubuntu 20.10,
Doesn't display checking DVD info messages as Kubuntu 20.10 does.
Then gets the following error messages and hangs.

Failed to start Snap Daemon
Failed unmounting /cdrom
Failed to start Ubuntu Live CD Installer...submit Kernel crash signatures...was shutdown

Created 3 DVDs on 3 different PC's running Mint, Kubuntu, & Windows 10 with the same Failure.
A work around is to place the ISO file on a USB Thumb drive (see below).

[claydoh]

As a DVD, have you verified the iso image, and tried burning at a slower speed? Tried different types/brands of disks?
iirc there is no automatic checking on the installer any longer, and checking the actual file downloaded is always a good idea
checksums
how to checksum

Is using the much more robust and well tested USB thumbdrive an option at all?


Hopefully the 21.04 section will be set up soon, I can't remember how to do this myself, and am working atm, so don't have the time to sit and figure it out.

[Snowhog]

I confirm installation failure.

I tried to install 21.04 twice in a VM. Both failures were with the installation of Grub. The first time Grub tried installing to to /dev/sda. The second time I specified /dev/sda1. Failure both times. Used Guided so I could see/set partition options.

I too, got the UEFI warning, but you just click OK/Continue twice and it proceeds.

Added:
To clarify, I chose btrfs as the FS. I forgot that Grub can?t write to a btrfs partition.

Added:
I struck out the bit about grub not being able to write to a btrfs partition, as checking on my KDE neon installation (also in a VM), it was installed on the single / partition I specified, and that partition is btrfs. So what's actually causing the grub installation failure here in 21.04?

[gh4wi]

Work around ...
Downloaded Kubuntu 21.04 and used Unetbootin to load to a USB drive.
New install of Kubuntu 21.04 to a SSD worked ok on same PC.
Installed ok, added favorite apps & tools, then AirVPN /w Open VPN, all ok.
But Clamtk would not scan, so deleted same.

[vanadiumboy]

I have a similar message.
The checksum on the ISO is good.
I burned the ISO to a DVD-RW. I used k3b on Kubuntu 20.10.
I tested on 2 different PCs.

It was saying something like
Failed to start Snap Daemon
Failed unmounting /cdrom <------------I don't think it displayed this
Failed to start Ubuntu Live CD Installer...submit Kernel crash signatures...was shutdown

[GreyGeek]

My son was attempting to install Kubuntu 21.04 in a hypervisor on his Win10 work computer and had the same problem. I installed 21.04 on my Kubuntu 20.04 system using qemu+kmv (by installing virt-manager).

I began like I have always done in the past: create an SDx1 partition and give it entirely to BTRFS mounted at "/", then installing the boot loader on SDx. That method failed on 21.04. It said I was missing a boot partition. So, I tried again by creating SDx1 with 500Mb and found a partition type near the bottom of the list that looked like it was for boot stuff, then I created SDx2 for holding the rest and giving it to BTRFS. That failed because it said I was missing an EFI (ESP) partition.

My computer is a 2012 Acer Aspire V3-771G that does not have UEFI. It is strictly a legacy system. But, I went ahead and repeated making SDx1 for boot, but this time I made SDx2 also at 500Mb for EFI, then I added SDx3 which was the rest of the drive, and making it BTRFS. That install worked.

An aside: I must say that I LIKE VERY MUCH what I see in Kubuntu 21.04. My virtual 21.04, to which I gave 8 of my 16GB of RAM and 4 of my 8 cores, runs every bit as fast as my 20.04 installed on the bare silicon. Those who work in a mixed Windows/Linux environment will love the implementation of Microsoft's Active Drive in 21.04. I love the default theme, I love the way the KDE Menu works, it is is lightening fast! However, I won't be switching to it because it will go away next January and I am not into short term releases. I am looking forward to Kubuntu's next LTS release. By then I expect Kubuntu to be even better than 21.04.

[steve7233]

I was thinking about upgrading to Kubuntu 21.04 but after GreyGeek said that it ends in January -about 7 months-, then I don't think it will be worth it since it's so short-lived.

[Beerislife]

21.04 installed just fine on a Lenovo B50-30 but when I tried it on a mid 2010 Mac Mini it installed but would only show a white screen on reboot. 20.04.2 works fine so I'll stick with that.

[Don B. Cilly]

Forgive the intrusion, but... I have this "cilly" theory, and I'd like to put it to y'all. Please correct me where I'm wrong.

It seems to me there are two "versions" of Kubuntu. One is Kubuntu "proper", the other is KDE neon.
The former focuses on more advanced/updated kernels and KDE apps, and is more conservative as to Plasma, the latter... the opposite.
Kubuntu, though, you have to continuously update the version yourself. Neon... not really.

Me, I'm not particularly interested in kernels and apps, more in Plasma development. So Neon is for me.
But if you are, and get your kernels via, say, UKUU, and apps via, say, appimage/snap/flatpak, why not just install Neon and have the best of both worlds?
You'd basically have yourself a rolling release, and not have to bother with upgrades, clean installs, and the like.
Or wouldn't you?

[gh4wi]

In my opinion Kubuntu 20.04 & 20.10 are the best versions.
Kubuntu 21.04 can be installed ok from USB, but does not install fro DVD...it needs work.

The last time I tried KDE Neon, I found it lacked features that are standard in Kubuntu.
Such as the ability to Auto-start scripts at start-up & shutdown.
I like to be able to automatically run Bleachbit at shutdown, so the next boot is not slowed down by all those junk files.
If KDE Neon now has this feature, please advise. If Not, I will stay with Kubuntu.

[claydoh]

I like to be able to automatically run Bleachbit at shutdown, so the next boot is not slowed down by all those junk files.

This is present in newer Plasma versions, and is not specific to any distro. IE the addition or lack of Plasma specific features in Neon will soon be seen in Kubuntu. 21.04 has the current major version at the moment, same as Neon.


It is however, not clear to those used to the previous UI:



No idea if the logout option ever went away, can't recall noticing that part.


But

Kubuntu 21.04 can be installed ok from USB, but does not install fro DVD...it needs work.

This probably has much more to do with your specific burner, its age and laser condition, as well as the media used, than it 'needing work'.
Plus far fewer volunteers testing DVD installs does not help.
The ISO image is identical no matter what media is used, and the USB actually emulates an optical disk, so it is essentially acting like a much faster, more reliable, longer lasting, more reliable, faster, less prone to bad writes, and cheaper in the long run, DVD.
That is much faster.

[jlittle]

There's much, much more to Kubuntu than KDE and kernels. There's a fantastic breadth of software in Ubuntu that Kubuntu gets. Ubuntu offers assurance that it all hangs together coherently.

For many software packages the isolation that snaps, flatpaks, app images and the like is good and makes the software work reliably and is easily updated. And for some software and some users, like plasma for the Neon folks, the builds of the latest versions are the best. I've been in that situation sometimes over the years with various projects.

But there's a lot of stuff that doesn't fit either approach. Some software is too fundamental to be isolated; file systems, compilers, and the init system spring to mind from my own experience. Hardware issues can need more than just an up to date kernel; f. ex. my desktop needs adventures with DKMS for ethernet to work reliably (thanks, Intel). I formed the impression that KDE Neon had some friction being based on 18.04 until it could rebase on 20.04.

Sent from my VFD 822 using Tapatalk

[Don B. Cilly]

Well, neon has been based on 20.04 for quite some time now.
I upgraded it "in place", had no issues. It also kept all my old Python2 stuff which would be a huff and puff to re-install from scratch.

Neon user is currently on Plasma 5.21.4 (Qt 5.15.2, FW 5.81.0).
The current kernel is 5.4.0-72.
Totally good enough for me.

[steve7233]

Forgive the intrusion, but... I have this "cilly" theory, and I'd like to put it to y'all. Please correct me where I'm wrong.

It seems to me there are two "versions" of Kubuntu. One is Kubuntu "proper", the other is KDE neon.
The former focuses on more advanced/updated kernels and KDE apps, and is more conservative as to Plasma, the latter... the opposite.
Kubuntu, though, you have to continuously update the version yourself. Neon... not really.

Me, I'm not particularly interested in kernels and apps, more in Plasma development. So Neon is for me.
But if you are, and get your kernels via, say, UKUU, and apps via, say, appimage/snap/flatpak, why not just install Neon and have the best of both worlds?
You'd basically have yourself a rolling release, and not have to bother with upgrades, clean installs, and the like.
Or wouldn't you?

Neon is NOT Kubuntu. Neon is from the KDE devs and uses core Ubuntu. You get the newest KDE packages. Kubuntu uses many of the KDE packages but they are not the latest. Neon's packages get updated quickly but Kubuntu tests them a while before updating and mostly uses Ubuntu Stuff. Major Kubuntu and neon updates use the latest core Ubuntu which means that Neon 21.04 will be out soon unless they decide to skip it due to a very sort life ending in January.

[Don B. Cilly]

Neon only re-bases on LTSs. No 21.x or the like.
And they usually take their time after a release to do so.
Of course it's not Kubuntu, but the difference is just in which packages are released and used in which - and when.
The are so much the same system, in practice, that for almost a year I had both sharing the same /home.
And the only application that didn't like it was... Firefox (nothing to do with Ubuntu). Minor glitch, complained about versions and tried to create a new profile if the two were not the same - all that was needed was to update the older one.
In the end I decided that for what I do I could just use neon. But really, what I have is Kubuntu. With a rolling Plasma.