How to leave BFQ as default instead of deadline? [Solved]

Does anyone know how I change the default from deadline to BFQ? BFQ has a lower latency, for desktop it makes no sense to use deadline because to copy files and do something else, the system starts to choke.

You can use udev rules.

Create a file in /etc/udev/rules.d called 60-ioschedulers.rules :

sudo nano /etc/udev/rules.d/60-ioschedulers.rules

The following lines will give you:

  1. bfq for non-rotatioal disks
  2. bfq also for rotational disks
  3. cdrom/dvdrom drives will remain at the default (mq-deadline)

:

## set scheduler for SSD and eMMC
ACTION=="add|change", KERNEL=="sd[a-z]|mmcblk[0-9]*", ATTR{queue/rotational}=="0", ATTR{queue/scheduler}="bfq"

## set scheduler for rotating disks
ACTION=="add|change", KERNEL=="sd[a-z]", ATTR{queue/rotational}=="1", ATTR{queue/scheduler}="bfq"

write out (ctl+o), then hit enter, then exit (ctl+x).

Reboot, or force new udev rules:

sudo udevadm trigger

As you probably already know, you can check what schedulers are in use with the command:

grep "" /sys/block/*/queue/scheduler

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see this
https://wiki.archlinux.org/index.php/Improving_performance#Changing_I/O_scheduler

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Thanks!

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