Prometheus suddenly creates huge "chunks_head" directory

[Manuel Díez Frutos]

I'm running prometheus on docker and I just realized that about 2h ago, there's a new directory in the storage folder (next to "wal" and all the other regular directories) called "chunks_head", and contains 450 files, named 025115 through 025564, each 512M in size.

Looking at disk usage graphs, it grew almost instantly to that size, the rests of the files in the storage folder are less than 200MB combined (I have been running it for a few days only). I have not been able to find anything about that directory, except for this unanswered stackoverflow question that has the same issue as me: https://stackoverflow.com/q/61986914/1364822

Thank you!

[Manuel Díez Frutos]

Okay, for whoever sees this in the future, it's being investigated: https://github.com/prometheus/prometheus/issues/7305