Comment 4 for bug 1827159

Currently experiencing this issue at customer site where there is a permission issue as nagios user can't access this directory, this particular mount point/directory is owned by root and the permission set on this is 700.

The -X tracefs is not working. Would a new check be needed for tracefs similar to the one for squashfs?

ubuntu@XXXXXXnagios-1:/snap/core/7270$ /usr/lib/nagios/plugins/check_disk -w '20%' -c '10%' -e
DISK CRITICAL - /sys/kernel/debug/tracing is not accessible: Permission denied

ubuntu@XXXXXXnagios-1:/snap/core/7270$ sudo ls -ld /sys/kernel/debug/tracing
drwx------ 8 root root 0 May 9 11:22 /sys/kernel/debug/tracing

ubuntu@XXXXXXXXnagios-1:/snap/core/7270$ mount | grep /sys/kernel/debug/tracing
tracefs on /sys/kernel/debug/tracing type tracefs (rw,relatime)