Hacker News Reader

Comment by traceroute66 | Hacker News Reader

> ZFS & BTRFS both have native FS checksumming, I don't think there's a strong reason not to use it, except maybe in a contained embedded context.

There are many good reasons not to use BTRFS. :)

Also ZFS is hell to use if you're not on an OS that has native support. You become reliant on e.g. kernel modules on Linux , and on Debian this means using Backports which is not something any sensible sysadmin wants to do because it introduces the hell of having a mismatch of all sorts of software unless you spend your life defining exclusions in the apt config.

Also in terms of SQLite, ZFS/BTRFS have no understanding of what's running on them. Personally, when it comes to databases I'd rather the database does its integrity checks. If the OS does some too that's great, but the database blindly assuming the OS will do integrity checking is not a good look in my book.

View on HN

> on Debian this means using Backports which is not something any sensible sysadmin wants to do because it introduces the hell of having a mismatch of all sorts of software unless you spend your life defining exclusions in the apt config.

  root@nas:/etc/apt/preferences.d# cat 80_kernel 
  Package: linux-image-amd64 linux-headers-amd64 linux-kbuild-*
  Pin: release n=bullseye-backports
  Pin-Priority: 1000

  root@nas:/etc/apt/preferences.d# cat 90_zfs 
  Package: libnvpair* libuutil* libzfs* libzpool* spl-dkms zfs-* zfsutils-linux zfsutils-linux-dev
  Pin: release n=bullseye-backports
  Pin-Priority: 1000

  root@nas:/etc/apt/preferences.d# cat 1000_backports 
  Package: *
  Pin: release n=bullseye-backports
  Pin-Priority: 10

Pretty sure this is well documented in many places, I definitely didn’t invent this wheel myself. Been running zfs on Debian this way for the last 3 releases. Had one instance of drama when the kernel was updated before the zfs package was updated, making me need to downgrade the kernel, which was a faff for sure.

The benefits of using ZFS in my environment greatly outweigh the downsides of using backports. I vastly prefer Debian to alternatives, so here we are (for me).

What exactly are the reasons to not use btrfs?

While btrfs is stable, it will not run heavy database loads well with the default settings.

https://archive.ph/dqFgh

Oracle explicitly does not support brtfs for their database.

That article is from 9 years ago. Is there any more recent review which comes to similar conclusions?

But also, if you’re running sqlite, your main goal is probably not to be a database server but to do some other primary objective that happens to benefit from using a database for some things.

I am not trying to run oltp on btrfs, so I don't personally need more recent knowledge.

A quick search suggests:

https://news.ycombinator.com/item?id=10257466

I am sure that you will find far more detail in your own research, should this motivate you. Good luck!

Here are some articles from 2022 and 2023. Btrfs database performance is still a disaster.

[1] https://www.enterprisedb.com/blog/postgres-vs-file-systems-p...

[2] https://www.phoronix.com/review/bcachefs-benchmarks-linux67

Reply on news.ycombinator.com