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Quick note on btrfs: unless you've been dealing with the latest kernels in the last few months, reserve judgement. Facebook has put a truly ridiculous number of

Quick note on btrfs: unless you've been dealing with the latest kernels in the last few months, reserve judgement. Facebook has put a truly ridiculous number of hours on that filesystem in the last year or so and fixed a concomitant number of issues.

walrus01 8y ago
From what I'm seeing in this thread, basically two things: People who have been running btrfs in production (reckless, imho) on kernels that are 2.5+ years old or worse. And then they're surprised and disappointed when it loses data. For everyone who's posted here with a btrfs data loss story, it would be helpful to quantify your anecdote with what kernel you were running.
- deno 8y ago
  Top post in this thread is about btrfs is on Tumbleweed, which is not an old kernel. My experiences have been similar. Btrfs is a great backup stress tool. I have no idea how Facebook is running it in production…
  - rb2k_ 8y ago
    The "how" consists mostly of reasonably up-to-date kernels that track main line as much as possible. As far as why, https://code.fb.com/open-source/linux/ https://code.fb.com/open-source/linux/ has a nice quote: "Btrfs has played a role in increasing efficiency and resource utilization in Facebook’s data centers in a number of different applications. Recently, Btrfs helped eliminate priority inversions caused by the journaling behavior of the previous filesystem, when used for I/O control with cgroup2 (described below). Btrfs is the only filesystem implementation that currently works with resource isolation, and it’s now deployed on millions of servers, driving significant efficiency gains."
    - deno 8y ago
      Is there any reason cgroup2 io can’t be implemented in non-CoW fs?
      - rb2k_ 8y ago
        I don't think copy-on-write is related (I don't know though)
  - cookiecaper 8y ago
    No one should underestimate the power of employing a system's maintainer. I'm sure one feels much more confident knowing that the primary author of the filesystem is available full-time to resolve any issues they may encounter. It's very common for MegaTechCos to hire maintainers like this, but us in the hoi polloi need to be cautious not to jump headfirst into a situation where we can't call upon the experts/inventors to get us out of any jam. We have to rely on our own abilities, the mailing list archives, and hopefully some relevant random blog posts that aren't too outdated. This should be taken into consideration much more often than it is. If anything, maintainer employment by a MegaTechCo should nix out their implied endorsement of the technology rather than taken as proof that it's viable.

walrus01 8y ago

From what I'm seeing in this thread, basically two things: People who have been running btrfs in production (reckless, imho) on kernels that are 2.5+ years old or worse. And then they're surprised and disappointed when it loses data. For everyone who's posted here with a btrfs data loss story, it would be helpful to quantify your anecdote with what kernel you were running.

deno 8y ago
Top post in this thread is about btrfs is on Tumbleweed, which is not an old kernel. My experiences have been similar. Btrfs is a great backup stress tool. I have no idea how Facebook is running it in production…
- rb2k_ 8y ago
  The "how" consists mostly of reasonably up-to-date kernels that track main line as much as possible. As far as why, https://code.fb.com/open-source/linux/ https://code.fb.com/open-source/linux/ has a nice quote: "Btrfs has played a role in increasing efficiency and resource utilization in Facebook’s data centers in a number of different applications. Recently, Btrfs helped eliminate priority inversions caused by the journaling behavior of the previous filesystem, when used for I/O control with cgroup2 (described below). Btrfs is the only filesystem implementation that currently works with resource isolation, and it’s now deployed on millions of servers, driving significant efficiency gains."
  - deno 8y ago
    Is there any reason cgroup2 io can’t be implemented in non-CoW fs?
    - rb2k_ 8y ago
      I don't think copy-on-write is related (I don't know though)
- cookiecaper 8y ago
  No one should underestimate the power of employing a system's maintainer. I'm sure one feels much more confident knowing that the primary author of the filesystem is available full-time to resolve any issues they may encounter. It's very common for MegaTechCos to hire maintainers like this, but us in the hoi polloi need to be cautious not to jump headfirst into a situation where we can't call upon the experts/inventors to get us out of any jam. We have to rely on our own abilities, the mailing list archives, and hopefully some relevant random blog posts that aren't too outdated. This should be taken into consideration much more often than it is. If anything, maintainer employment by a MegaTechCo should nix out their implied endorsement of the technology rather than taken as proof that it's viable.