I see no one mentined yet: BTRFS is slow on HDDs. It trivially comes from BTRFS
being COW. So if you changed a bit in a file, BTRFS will copy a block (or maybe
a number of them, not sure this detail matters) to another place, and now your
data got fragmented. SSDs may not care, HDDs on the other hand do.

There's a defrag option, but this means that at random times BTRFS will hog your
IO. And HDDs doesn't really have much of a room to hog.

Another reason worth mentioning: BTRFS per se is slow. If you look at benchmarks
on Phoronix comparing BTRFS with others, BTRFS is rarely even on par with them.

As a matter of fact, I have two Archlinux laptops on BTRFS with compression,
both only have HDD. I've been using for 3-4 years BTRFS there I think, maybe
more. I made use of BTRFS because I was hoping that using ZSTD would result in
less IO. Well, now my overall experience is that it is not rare that systems
starting to lag terribly, then I execute `grep "" /proc/pressure/*`, and see
someone is hogging IO. Then I pop up `iotop -a` and see among various processes
a `[btrfs-cleaner]` and `[btrfs-transacti]`. It may be because of defrag option,
I'm not sureā€¦

devel mailing list -- devel@lists.fedoraproject.org
To unsubscribe send an email to devel-le...@lists.fedoraproject.org
Fedora Code of Conduct: 
List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
List Archives: 

Reply via email to