Open linyinfeng opened 2 years ago
Current GC logic deletes dead narinfo files along with the nar files they referring to. But live narinfo files can still refer to these deleted nar files, because multiple narinfo files may have same URL. https://github.com/tuna/tunasync-scripts/blob/a47eb031f58083f5a016c5090b233d22bd4b6b04/nix-channels.py#L429-L438
Narinfo file example:
# github:nixos/nixpkgs/e10da1c7f542515b609f8dfbcf788f3d85b14936#element-web $ curl https://cache.nixos.org/hdz90ld1wwj6nwp580avv02v62cjh7h3.narinfo StorePath: /nix/store/hdz90ld1wwj6nwp580avv02v62cjh7h3-element-web-1.10.10 URL: nar/0ji0p1g4fjwpqmf33maf7irznb2wclzi483hicyyjifybh43qxrs.nar.xz Compression: xz FileHash: sha256:0ji0p1g4fjwpqmf33maf7irznb2wclzi483hicyyjifybh43qxrs FileSize: 13688456 NarHash: sha256:0r3pdgcnrlvf56cxlgxdsai5f1k9pf7cq80zssrbfbabrasbkk2v NarSize: 43380024 References: Deriver: af669vfa956f7znxarma0rf1883nxy8k-element-web-1.10.10.drv Sig: cache.nixos.org-1:T0b6vIGHgFC2E9SspFsf/MMubYixGGYna/JOssawEaQh4jdoyJNAkRNN9pJDFJDTPKER7DCXAVXE5zgzYedPBw== # github:nixos/nixpkgs/c30945a93fbd3122a55ee6a63c9bfef7556bc82e#element-web $ curl https://cache.nixos.org/zgwkj12lfii1ii041497bxm8rzcx23sd.narinfo StorePath: /nix/store/zgwkj12lfii1ii041497bxm8rzcx23sd-element-web-1.10.10 URL: nar/0ji0p1g4fjwpqmf33maf7irznb2wclzi483hicyyjifybh43qxrs.nar.xz Compression: xz FileHash: sha256:0ji0p1g4fjwpqmf33maf7irznb2wclzi483hicyyjifybh43qxrs FileSize: 13688456 NarHash: sha256:0r3pdgcnrlvf56cxlgxdsai5f1k9pf7cq80zssrbfbabrasbkk2v NarSize: 43380024 References: Deriver: 51mif1gp7i3igq8d9a9aff073qn9drd4-element-web-1.10.10.drv Sig: cache.nixos.org-1:kAT7/4P/GNm0kmFoTss6klYET4ZdYjNhs7OW3q3jDIQMXZqiTdXyZ8uLW0k2eiyuusgdBOSHzvZpcRjxWUFXBw==
Names of nar archives on https://cache.nixos.org are their base32 hashs. For example:
$ nix hash file <(curl https://cache.nixos.org/nar/1jh8kd7ql2v73fdspp1v08hvfdfxjvl2i86g409ckgpy8k6l41g8.nar.xz) | \ xargs nix hash to-base32 1jh8kd7ql2v73fdspp1v08hvfdfxjvl2i86g409ckgpy8k6l41g8
Confirmed. Practically though this seems to only occur really rarely and should not noticably impact usage.
Current GC logic deletes dead narinfo files along with the nar files they referring to. But live narinfo files can still refer to these deleted nar files, because multiple narinfo files may have same URL. https://github.com/tuna/tunasync-scripts/blob/a47eb031f58083f5a016c5090b233d22bd4b6b04/nix-channels.py#L429-L438
Narinfo file example:
Names of nar archives on https://cache.nixos.org are their base32 hashs. For example: