Below I’m only describing the changes relative to the previous tutorial.

Firstly, the location of guppy binaries changed. So in order to know the version, you’ll need to execute

/opt/ont/guppy/bin/guppy_basecall_server -v # in my case it’s ver. 5.0.11

Secondly, it seems ONT started to distribute guppy as a service starting from MinION 21.06.0. Because of that, changing MinION configuration has no effect on the service itself.

So in order to enable GPU basecalling, you’ll need to edit the guppyd.service in /etc/systemd/system/guppyd.service.d/override.conf to something like this

ExecStart=/opt/ont/guppy/bin/guppy_basecall_server --log_path /var/log/guppy --config dna_r9.4.1_450bps_fast.cfg --port 5555 --device cuda:all

And naturally reload and restart all relevant services:

sudo systemctl daemon-reload
sudo service guppyd stop && sudo service minknow stop && sudo service minknow start