How long is binary cache kept on

I’ve found a really old mailing-list message saying that binary cache is kept forever. Is that still true?
Some package managers such as brew and alpine package manager retains only recent versions of packages to save cost.

[Nix-dev] retention

so far it’s still true


Thank you, but is this written somewhere in documentation?

No, but IIRC, the packages are compressed before being put on the cache, so the bill for the s3 bucket is very small in comparison to everything else (hydra workers, etc).

Last figure I heard was that the entire cache was below 5-8TB. Which is pretty low on the return-on-intention.

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Maybe in the future, there will be something in place to prune items that haven’t been accessed in N years, but there’s hasn’t been a motivating reason to do so yet.

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Cache size is around 220TB. No plans to change retention, afaik.

That’s also why it was a design decision for Cachix to support GC as it’s hard to justify an ever-growing expense when budgeting.


Ah, I was only off by a factor of 40 :wink: