prometheus/node_exporter · error

getmntinfo() failed

Error message

getmntinfo() failed

What it means

The BSD/macOS getmntinfo(3) C call returned a mount count of 0, which the collector treats as failure to enumerate mounted filesystems. GetStats depends entirely on this list; without it no node_filesystem metrics can be produced. Note getmntinfo also returns 0 on genuine empty mount tables, so this can fire spuriously in restricted environments (e.g. some containers).

Solutions

1. Verify mounts exist on the host (run `mount`); on macOS this failing usually indicates a libc memory allocation failure inside getmntinfo.
2. If running in a container or sandbox, mount /proc-like filesystems or run without the isolation that hides mount tables, or disable the filesystem collector (--collector.filesystem).
3. Retry scraping; transient getmntinfo failures (ENOMEM) usually resolve on the next scrape.

When it happens

Trigger: Thrown at collector/filesystem_macos.go:67 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of prometheus/node_exporter@17ddd77c59 (2026-09-07). Data as JSON: /api/errors/fc974cbdd4fa5c6a. Report an issue: GitHub.

Appendix: source

Thrown at collector/filesystem_macos.go:67

import "C"

import (
	"errors"
	"unsafe"
)

const (
	defMountPointsExcluded = "^/(dev)($|/)"
	defFSTypesExcluded     = "^devfs$"
	readOnly               = 0x1 // MNT_RDONLY
)

// Expose filesystem fullness.
func (c *filesystemCollector) GetStats() (stats []filesystemStats, err error) {
	var mntbuf *C.struct_statfs
	count := C.getmntinfo(&mntbuf, C.MNT_NOWAIT)
	if count == 0 {
		return nil, errors.New("getmntinfo() failed")
	}

	mnt := (*[1 << 20]C.struct_statfs)(unsafe.Pointer(mntbuf))
	stats = []filesystemStats{}
	for i := 0; i < int(count); i++ {
		mountpoint := C.GoString(&mnt[i].f_mntonname[0])
		if c.mountPointFilter.ignored(mountpoint) {
			c.logger.Debug("Ignoring mount point", "mountpoint", mountpoint)
			continue
		}

		device := C.GoString(&mnt[i].f_mntfromname[0])
		fstype := C.GoString(&mnt[i].f_fstypename[0])
		if c.fsTypeFilter.ignored(fstype) {
			c.logger.Debug("Ignoring fs type", "type", fstype)
			continue
		}

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