Faster DNF updates
I want to saturate my crappy Canadian internet connection

We’ve all sat through a very slow dnf update. While in a rush to get out the door, I realized it was going much slower than it should.

It seems the mirrors limit the maximum speed of each single file.

So I added the following under the existing [main] section in my /etc/dnf/dnf.conf:

fastestmirror=True
max_parallel_downloads=16

It turns out you can even set this to 20, but 16 seemed plenty for me. Note that this is not the max_downloads_per_mirror option, so I am not hosing any one particular mirror by doing this.

In my testing, these settings sped things up. Note that fastestmirror uses TCP latency rather than available bandwidth to choose a mirror, so your results may vary.

You can enable these settings for a one-shot CLI run with:

dnf update --setopt=fastestmirror=True --setopt=max_parallel_downloads=16

If you use mgmt config, then you get this automatically without even thinking about it. Use our misc.dnf_update class to just update the right way.

We’re building a growing compendium of “just works in a polished and tuned way” configurations, and we’d love to share them with you.

The remaining bottleneck appears when a large download is still running after all the smaller downloads have finished. Prioritizing the largest files first could reduce that tail latency. Upstream feature request, anyone?

Watch chromium and firefox race.

If anyone can propose a higher parallel-download default and the scheduling feature to the right people, I’d appreciate it.

I never upgrade my Fedora until about two weeks or so after the N-1 release, and since Fedora 45 is just around the corner, it will be soon time to upgrade to Fedora 44. To do so you can use:

sudo dnf system-upgrade download --setopt=fastestmirror=True --setopt=max_parallel_downloads=16 --releasever=44

Overall, this reduced my overall download time from a projected three hours to under ten minutes.

I’m not sure why the parallel-download default isn’t higher, but I hope this makes your day go by faster.

Happy hacking!

James

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October 1, 2026
402 words

• technical