LibBPQ logs most bits to /var/log/syslog
This also includes some very chatty 'Heartbeats'
May 13 22:38:39 linbpq_box1 LINBPQ[5905]: BPQ32 Heartbeat Buffers 998 APRS Queues 0 0#015
To save SD card writes, you can re-direct this out to RAM (/run - or somewhere else that is RAM on your system)
To do this, you need to create a new file
/etc/rsyslog.d/00-linbpq-buffers.conf
and add to it:
if $msg contains 'BPQ32 Heartbeat' then /run/linbpq-buffers.log & STOP
( note, if you are on an older version on rsyslog, you need & ~ instead of & STOP )
Then restart rsyslogd
sudo systemctl restart rsyslogd
This may fill up your RAM, so you can do several things
To use logrotate, to compress the files and only keep 7 days:
Create a file
cat /etc/logrotate.d/linbpq-buffers
Add this to the file
/run/linbpq-buffers.log { rotate 7 daily missingok compress }