Restrict Fstype for Disk Fill Alert

[xixipangma]

After adding Alert 2.7, I noticed that i'm getting disk fill alerts for /run/user/1113 mountpoint, since the rule will apply to all fstype labels of tmpfs as well. Perhaps we should set rule to restrict it to ext4 and xfs etc or may be add a not equal to condition to rule out tmpfs ?

predict_linear(node_filesystem_free_bytes{fstype=~"ext4|xfs"}[1h], 4 * 3600) < 0

[samber]

Should be better if we exclude this specific fstype:

predict_linear(node_filesystem_free_bytes{fstype!~"tmpfs"}[1h], 4 * 3600) < 0

[paulfantom]

That's unfortunate. tmpfs is frequently used for directories which should be pruned on node reboot, but filling them up during operations can cause problems with system. A good example is a website which allows uploading files. By default webserver will use a temporary directory for storing uploaded chunks, which then will be copied as a file to a target directory. So if you fill up temporary dir, you should have alert as this won't allow for future uploads and impact site. Another example would be to have /var/log as tmpfs when you have a centralized log solution.
Those are the reasons why in official node_exporter mixins fstype is a configurable option and why hardcoded exclusion of tmpfs shouldn't be implemented.

[paulfantom]

@xixipangma why not exclude that mountpoint from node_exporter with collector.filesystem.ignored-fs-types or collector.filesystem.ignored-mount-points?