prometheus/node_exporter · error

couldn't get proc/swap information

Error message

couldn't get proc/swap information: %w

What it means

Reading swap entries from procfs failed: c.fs.Swaps() could not open or parse /proc/swaps inside getSwapInfo. This fires when the /proc/swaps file is absent or unreadable, which occurs on systems with swap entirely disabled (no swap devices configured) or in hardened containers where procfs is restricted; the wrapped error carries the procfs cause. The error propagates up through Update, so the swap collector fails that scrape instead of emitting zeroed or partial swap metrics.

Solutions

1. Verify `cat /proc/swaps` works and shows the expected column layout.
2. Ensure the file is readable by the exporter user.
3. Retry; transient errors resolve on the next scrape.

When it happens

Trigger: Thrown at collector/swap_linux.go:65 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/d83304ede331d5f1. Report an issue: GitHub.

Appendix: source

Thrown at collector/swap_linux.go:65

	return &swapCollector{
		fs:     fs,
		logger: logger,
	}, nil
}

type SwapsEntry struct {
	Device   string
	Type     string
	Priority int
	Size     int
	Used     int
}

func (c *swapCollector) getSwapInfo() ([]SwapsEntry, error) {
	swaps, err := c.fs.Swaps()
	if err != nil {
		return nil, fmt.Errorf("couldn't get proc/swap information: %w", err)
	}

	metrics := make([]SwapsEntry, 0, len(swaps))

	for _, swap := range swaps {
		metrics = append(metrics, SwapsEntry{Device: swap.Filename, Type: swap.Type,
			Priority: swap.Priority, Size: swap.Size, Used: swap.Used})
	}

	return metrics, nil
}

func (c *swapCollector) Update(ch chan<- prometheus.Metric) error {
	swaps, err := c.getSwapInfo()
	if err != nil {
		return fmt.Errorf("couldn't get swap information: %w", err)
	}

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