Werk #19834: Linux memory: new graphs for newer kernel fields and fixed graph totals
| Component | Checks & agents | ||
| Title | Linux memory: new graphs for newer kernel fields and fixed graph totals | ||
| Date | Oct 1, 2026 | ||
| Level | Prominent Change | ||
| Class | New Feature | ||
| Compatibility | Compatible - no manual interaction needed | ||
| Checkmk versions & editions |
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The Memory service of Linux hosts has new graphs for memory fields that newer kernels report: Slab, Misc memory types, Contiguous memory allocator, Zswap, RAM used by GPU drivers and VM guest memory. The GPU graph shows system memory that GPU drivers hold, not the graphics card's own memory. Metrics that showed up as separate single-metric graphs are now part of these or of existing graphs.
Three graphs showed wrong totals and are fixed:
- Swap: swap cached is part of swap used and is no longer stacked on top of it.
- Caches: only reclaimable slab counts as cache, matching the cache total Checkmk subtracts from used RAM.
- Memory committing: the commit limit is a line, no longer stacked on top of the committed memory.
Bounce buffers are no longer part of Disk Writeback and its graph. They are block layer copies, not data waiting to be written, and kernels since 6.16 always report them as zero. They are now shown in Misc memory types.
MemAvailable is now called "Available RAM (kernel estimate)" in its graph, in the ruleset Memory levels for Linux and in the service output. If you are using rules which match on service output for "RAM available", please adapt these rules.