There’s been some Friday night kernel drama on the Linux kernel mailing list… Linus Torvalds has expressed regrets for merging the Bcachefs file-system and an ensuing back-and-forth between the file-system maintainer.

  • Semperverus@lemmy.world
    link
    fedilink
    English
    arrow-up
    8
    arrow-down
    1
    ·
    3 months ago

    This probably meets some extreme corporate usecase where they are serving millions of customers.

    • DaPorkchop_
      link
      fedilink
      arrow-up
      18
      ·
      edit-2
      3 months ago

      It’s not that obscure - I had a use case a while back where I had multiple rocksdb instances running on the same machine and wanted each of them to store their WAL only on SSD storage with compression and have the main tables be stored uncompressed on an HDD array with write-through SSD cache (ideally using the same set of SSDs for cost). I eventually did it, but it required partitioning the SSDs in half, using one half for a bcache (not bcachefs) in front of the HDDs and then using the other half of the SSDs to create a compressed filesystem which I then created subdirectories on and bind mounted each into the corresponding rocksdb database.

      Yes, it works, but it’s also ugly as sin and the SSD allocation between the cache and the WAL storage is also fixed (I’d like to use as much space as possible for caching). This would be just a few simple commands using bcachefs, and would also be completely transparent once configured (no messing around with dozens of fstab entries or bind mounts).

      • MrSpArkle@lemmy.ca
        link
        fedilink
        arrow-up
        2
        ·
        3 months ago

        Is there a reason for bind mounting and not just configuring the db to point at a different path?

    • pimeys@lemmy.nauk.io
      link
      fedilink
      arrow-up
      1
      ·
      3 months ago

      I mean… If you have a ton of raw photos in one directory, you can enable the highest compression rate with zstd to it. Every other directory has lz4 with the fastest compression. Your pics take much less space, but the directory will be slower to read and write.