Nextcloud version (eg, 20.0.5): 26.0.5
Operating system and version (eg, Ubuntu 20.04): Ubuntu 22.04
The issue you are facing:
apt update leads to:
Err:6 https://mirror.kumi.systems/mariadb/repo/10.8/ubuntu jammy Release
404 Not Found [IP: 135.181.208.35 443]
Hit:7 Index of /ubuntu jammy-security InRelease
Reading package lists… Done
E: The repository ‘https://mirror.kumi.systems/mariadb/repo/10.8/ubuntu jammy Release’ no longer has a Release file.
N: Updating from such a repository can’t be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
Is this the first time you’ve seen this error? (Y/N): Y
Steps to replicate it: apt update
Nextcloud versions seem to have some relationship to corresponding mariadb version, so I want to avoid traps.
Would upgrade to NC 26.0.9 solve the problem? Or go to some NC 27.*?
The issue is with Ubuntu. For some reason your system cannot locate 10.8 mariadb from jammy. The repo isn’t working. First thing is to check your actual Ubuntu installation, then check the apt repository.
MariaDB 10.8 was a short-term release that has been End of Life since May of this year, and as @just already mentioned, it appears that the repos for this release are no longer available:
So MariaDB is not upgraded with NC upgrades? Doesn’t seem logical to me as I found several mentions, that “this NC version only works with this MariaDB version x”.
So there is no risk upgrading MariaDB independently?
Again: Wouldn’t upgrading my NC version also solve the problem? And yes, I did see @just mentioning, that this is a problem of my Ubuntu installation.
There’s no problem with your Ubuntu installation. The repo you added when you installed MariaDB no longer exists because the version of MariaDB it served is no longer maintained.
No, if you do a manual installation, you’re responsible for managing all the dependencies such as database, PHP, web server, etc. But you could have used 10.6 (long-term) instead of 10.9 (short-term), which is still the recommended version by Nextcloud.
Or you could have used the version from the Ubuntu repos, instead of adding the repo for a short-term release version that was only supported for one year.
If you are looking for an all-in-one solution that does everything for you, I’d suggest you have a look at https://nextcloud.com/all-in-one/
Well, there’s always a certain risk of something going wrong, so you should definitely have a BACKUP! before you start. However if you read the documentation on how to upgrade between major releases of MariaDB, and as long as you only upgrade to a version that works with Nextcloud, you should be fine.
Also, while 10.6 is still the recommended version by Nextcloud, 10.11 will definitely work. So I’d recommend upgrading to that, as downgrading MariaDB is not officially supported.
Since you you do not provide any details, I can only give you a general answer, assuming you’re using Ubuntu as well…
Apt repositories are either included directly in the file /etc/apt/sources.list or in a separate file under /etc/apt/sources.list.d/.
Delete or comment out the respective lines in /etc/apt/sources.list or delete the file under /etc/apt/sources.list.d/.
After that, you should also remove the key for the repo from apt. You can do so by running apt-key list, which will list all keys for all repos. Find the one for MariaDB and delete it with apt-key del <key id>.
IMPORTANT: Make sure you got the correct key id, if you accidentally delete a key from another repo, that repo will no longer work.