How to resume pacman package downloads?

Question

I'm trying to install some updates while on a sketchy connection in Arch Linux. What is the best way to do that?

while ! pacman --noconfirm --needed --refresh --upgrade
do
    :
done

took over 90 minutes to complete. Possibly this is because I used the strangely named --upgrade option which is for reinstalling packages rather than doing a package upgrade (--sysupgrade).

Solution 1

This isn't pacman's default behaviour: if the package has been successfully downloaded (ie., is not considered corrupt either due to incomplete downloading or a failed hash sum), then pacman shouldn't download the same package again. If the package has been partially downloaded, pacman will resume downloading where it left off without you doing anything special.

You could also look at using a wrapper like Powerpill to assist with downloading over a flaky connection.

Solution 2

Just new to Arch, so maybe I am missing something.

For me pacman did not resume file downloads by default and together with my flaky Internet connection it was impossible to install packages bigger than about 1MB. It just started over again and again and never finished.

After some investigation in the pacman.conf docs, I used...

DisableDownloadTimeout

XferCommand = /usr/bin/wget --passive-ftp -c -O %o %u

...as well as...

UseDelta = 0.7 # a little extra

...to mitigate Germany's mobile Internet shortcomings. Now it resumes just fine.

Comments

[hanetzer]

Exactly what I was thinking

[l0b0]

Interesting settings. UseDelta = 0.7 is the default according to man pacman.conf.

[Admin]

Ah, right. Initially I wanted to change that value but then struggled to understand the description and left it as it was predefined in pacman.conf. :)