What does `docker system prune -a` actually do?

Question

My empty space before running docker system prune -a was 900 MB and running it gives me 65 GB free space although the command report that it cleaned only 14.5 GB

Is the report is just wrong on am I missing something here?

The docs is not telling something new and it would be normal if it clears only 14.5 GB and this only gives me one answer that I'm doing it in a wrong way. Any thoughts here?

I've added an answer here that provides a detailed explanation of what `docker system prune -a` is doing - https://stackoverflow.com/a/73536542/1549918 — Chris Halcrow, Aug 30 '22 at 02:35

score 4 · Accepted Answer · edited Aug 29 '22 at 02:24

4

This will remove following content form your host machine where docker is running

    - all stopped containers
    - all networks not used by at least one container
    - all images without at least one container associated to them
    - all build cache

edited Aug 29 '22 at 02:24

Chris Halcrow

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answered Jul 15 '20 at 13:15

Dashrath Mundkar

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Thanks for your quick answer , but the I'm looking for why it report for only 14.5 GB but actually it frees around 64 GB – Mohamed Abu Galala Jul 15 '20 at 13:19
And maybe it is something under the hood in docker itself and maybe there is no right answer for my question at all – Mohamed Abu Galala Jul 15 '20 at 13:21
@MohamedAbuGalala when you run above command how much Total reclaimed space was there? – Dashrath Mundkar Jul 15 '20 at 13:21
around 64 GB ##### – Mohamed Abu Galala Jul 15 '20 at 13:23

What does `docker system prune -a` actually do?

1 Answers1