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.
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)
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. XXXXXXnagios- 1:/snap/ core/7270$ /usr/lib/ nagios/ plugins/ check_disk -w '20%' -c '10%' -e debug/tracing is not accessible: Permission denied
ubuntu@
DISK CRITICAL - /sys/kernel/
ubuntu@ XXXXXXnagios- 1:/snap/ core/7270$ sudo ls -ld /sys/kernel/ debug/tracing debug/tracing
drwx------ 8 root root 0 May 9 11:22 /sys/kernel/
ubuntu@ XXXXXXXXnagios- 1:/snap/ core/7270$ mount | grep /sys/kernel/ debug/tracing debug/tracing type tracefs (rw,relatime)
tracefs on /sys/kernel/