ci/nix-install-ephemeral: Drop sticky disk config - #2346
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samrose
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Aug 6, 2026
mmlb
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August 6, 2026 15:10
I noticed that its taking nix-eval almost 9m to install nix when on my laptop it takes about 8s. Initially I thought it was something in blacksmith and reached out to support. They pointed at nix install (actual nix, not the action) doing chown on /nix as the culprit. Not sure why we are using sticky disks when we have a binary cache we push to and also call nix-eval-jobs with `option eval-cache false`. So seems like we a pure loss. Dropping this brought the nix install action down to 8s and the overall nix-eval from ~10m -> ~3m.
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…c-spool-path-defaults-onto-the-10gb-root-volume * origin/develop: (26 commits) Lots of bootstrap script clean ups (#2326) ci: Fix nix-build PUSH_TO_CACHE (#2345) ci/nix-install-ephemeral: Drop sticky disk config (#2346) chore: bump postgres_release to cut fresh AMIs (includes #2334) (#2349) fix(multigres): stop base config data_directory from overriding pooler data dir (#2344) fix(cron): remove unnecessary TRIGGER grant on cron.job_run_details from postgres (#2334) chore: enable extension version restriction (warn) and cut AMIs (#2315) feat(nix): add site-env packages for rolling instance updates (#2283) ci: resolve package install sha from a flake input override (#2327) fix(multigres): remove dangling wal-g include from postgresql.conf (#2338) fix: Allow test CI pipelines to use old Int CA access. For staging only (#2330) chore(nix): remove maintainers field from package definitions (#2280) chore: bump multigres to b713432 (#2323) ci: Use arm-native-runner for kvm builds on aarch64-linux (#2319) Whole lot of ansible clean up (#2272) fix(ansible): drop no-op zpool loop item from zswap task (#2322) ci: Fix dockerhub-release-matrix matrix generation (#2320) chore: bump pgctld (#2318) fix(ansible): skip zswap params the kernel does not expose (#2321) feat(docker): add Dockerfile-supabase base image and rewrite Dockerfile-multigres as layered image (#2160) ...
hunleyd
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…nix-pkg-for-pgbackrest * origin/develop: (36 commits) Lots of bootstrap script clean ups (#2326) ci: Fix nix-build PUSH_TO_CACHE (#2345) ci/nix-install-ephemeral: Drop sticky disk config (#2346) chore: bump postgres_release to cut fresh AMIs (includes #2334) (#2349) fix(multigres): stop base config data_directory from overriding pooler data dir (#2344) fix(cron): remove unnecessary TRIGGER grant on cron.job_run_details from postgres (#2334) chore: enable extension version restriction (warn) and cut AMIs (#2315) feat(nix): add site-env packages for rolling instance updates (#2283) ci: resolve package install sha from a flake input override (#2327) fix(multigres): remove dangling wal-g include from postgresql.conf (#2338) fix: Allow test CI pipelines to use old Int CA access. For staging only (#2330) chore(nix): remove maintainers field from package definitions (#2280) chore: bump multigres to b713432 (#2323) ci: Use arm-native-runner for kvm builds on aarch64-linux (#2319) Whole lot of ansible clean up (#2272) fix(ansible): drop no-op zpool loop item from zswap task (#2322) ci: Fix dockerhub-release-matrix matrix generation (#2320) chore: bump pgctld (#2318) fix(ansible): skip zswap params the kernel does not expose (#2321) feat(docker): add Dockerfile-supabase base image and rewrite Dockerfile-multigres as layered image (#2160) ...
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What kind of change does this PR introduce?
Feature
What is the current behavior?
We use blacksmith sticky disks in nix-eval workflow and the underlying nix install process chowns /nix. The dir is ever growing and now has enough files that the chown takes an immense amount of time ~9m. We don't even really need the sticky disk since we call nix-eval-jobs with
option eval-cache falseand already have the s3 backed binary cache.What is the new behavior?
No sticky disk, no chown for 9m, nix-eval goes from ~11m -> ~3m.
Additional context
It might make sense to use sticky disk as a faster binary cache, worth looking into.
Fixes PSQL-1599