thin-pool-metadata · shipping · also LVM thin-pool metadata

Thin-pool metadata

The dm-thin mapping and allocation information stored in a separate logical metadata device to track how thin volumes use a pool's data blocks.

The active LVM component has a _tmeta suffix. It is distinct from volume-group configuration metadata. A _pmspare is used as repair output, not active free metadata capacity or a current backup. [1] Linux v6.12 distinguishes metadata-space mode from failed metadata operations; inspect needs_check and logs, not just Meta% or ro. [2]

vgcfgbackup omits these mappings. A reserve_metadata_snap inspection view is not a thin-volume data snapshot, and exporting mappings does not copy payload blocks. thin_dump 0.9.0 requires metadata-snapshot mode when reading live metadata. [1] [4] [5]

Relations

related

thin-pool, thin-provisioning, lvm, snapshot

Limitations

• A repaired mapping structure does not by itself verify filesystem or application consistency. [1]

Citations

1. LVM2 lvmthin(7): pool components, usage counters and metadata repair (accessed 2026-10-17)
2. Linux v6.12: dm-thin.c, pool modes, timeout, failed metadata operations and resize (accessed 2026-10-17)
4. Linux v6.12 dm-thin: create_snap and reserve_metadata_snap are different operations (accessed 2026-10-17)
5. thin-provisioning-tools 0.9.0: thin_dump(8), live-metadata restrictions and output formats (accessed 2026-10-17)

Further reading

3. Hesela: Sparse files, preallocation and thin-pool capacity (accessed 2026-10-17)

JSON: /data/terms/thin-pool-metadata.json