Pacman -Syyuu after mirrors update

Yesterday i’ve done a deep dive into a lot of topics on archwiki :hole: :rabbit2:

And now i have a question :upside_down_face:

Warning: In most cases if you force refresh the pacman database, you will want to force downgrade any potentially too-new packages to correspond to the versions offered by the new mirror. This prevents issues where packages are inconsistently upgraded, leading to a partial update.

pacman -Syyuu

This is not necessary when using timestamps to ensure the mirrors are only upgraded.

© https://wiki.archlinux.org/index.php/Mirrors#Force_pacman_to_refresh_the_package_lists


What exactly is meant here by:

This is not necessary when using timestamps to ensure the mirrors are only upgraded.

?

That probably means when you use Sy instead of Syy.

Excluding Manjaro, there are not many reasons to use Syy on Arch-based distros in my opinion. I would think unless you were on a mirror sufficiently broken enough to have bad timestamps this shouldn’t be needed.

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Well…Yeah i kinda think of my Manjaro experience too…
I was always doing -Syyuu back then after updating mirrors.

But on Arch you still would need to do -Syy after any mirrorlist edit / update anyway, right?

That’s exactly my question, how do you check / know that with something like reflector or anything else, to 100% avoid such situation?

You really shouldn’t have to. Changing mirrors shouldn’t impact the timestamps of the databases.

I suppose if you want to 100% avoid that situation you could use Syy when you switch mirrors but I think we are talking about a pretty extreme edge case.

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On Arch you only need syyuu when you are using the testing mirrors and the system breaks then you adjust the mirrors to go back to stable. Or you use Arch rollback machine, as then you can rollback to any date https://wiki.archlinux.org/index.php/Arch_Linux_Archive very good idea like using timeshift for packages

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I don’t really plan to use testing mirrors on Arch, that’s too extreme for me…yet :sweat_smile:


Sorting mirrors

It is recommended to repeat this process before every system upgrade to keep the list of mirrors up-to-date.

Based on what have been said here, i assume this is also overkill archwiki advice for most cases, unless you have some very broken mirrors on your list, which should be noticeable during update anyway if something fails?

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That seems like pretty severe overkill unless you are in a situation with a fragile/inconsistent network.

The most common issue with a broken mirror would be that you would stop getting updates which given how often updates happen should be pretty noticeable for most people.

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I only use testing no problems most of the time when it does happen once this year i just # out the testing did Syyuu that removed testing and took me back to stable 2 days later uncommented testing Syyu back on testing all fine since.

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The only place this command ever has a remote sense of validity is if you are switching mirrors to a mirror which you positively know is of an earlier date than your current mirror.

The command will balance your current system with the remote database - replacing newer versions with older versions.

Using commands like this to replace a faulty release of Firefox doesn’t present issues - downgrading base system packages - no guaranties implied and it is usually a bad idea especially when you are downgrading system packages (kernel, kernel modules etc - mostly low level stuff).

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Never had a problem downgrading using syyuu it does basically the same as timeshift and if you go further and use the rollback mirrors everything on the system is downgraded to the date specified by you. No more dangerous than updating.

No offense - years of running computers have teached me there is nothing which can be applied cross systems.

Years of running computers Arch mainly have taught me that the Arch way is the only way to update, downgrade a Arch based system, I would rather trust Arch Linux than a user no offense by the way

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I did say - think twice before doing anything like -Syyuu

Your fine you should think twice about doing anything even turning the system on, Lol my experiance is Arch Linux is virtually unbreakable if you do things the arch way meaning you never need to reinstall. Mainly common sense gets you up and working

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