Output ramdisk data to influx2

I have a ramdisk (tmpfs) that I put in Telegraf:

[[inputs.disk]]
  mount_points = ["/tmp/ramscratch"]
#  ignore_fs = ["devtmpfs", "devfs"]

Is there a reason why this isn’t send to Influxdb2?
What is the best practise if you want to monitor reads/writes of the ramdisk in Grafana with Flux query?

The disk plugin monitors information about disk usage, specifically from /proc/self/mounts. This is laid out in the plugin readme: telegraf/plugins/inputs/disk at master · influxdata/telegraf · GitHub

For performance data, you want to look at the diskio plugin, which looks at the /proc/diskstats and /sys/block/<dev>/stat files. Off-hand I’m not sure your ramdisk will have things in those, but look there. Plugin readme: