nfs-state-reclaim · shipping · also NFS lock reclaim, NFS open reclaim

NFSv4 state reclaim

NFSv4 state reclaim is the recovery of previously held open and locking state after the server loses that state, rather than the acquisition of unrelated new locks.

In NFSv4.1, clients reclaim eligible state during server recovery and send RECLAIM_COMPLETE when finished. Before obtaining new locking state with a new client ID, the global form (rca_one_fs = FALSE) is required even when there is nothing to reclaim. The file-system-specific form (rca_one_fs = TRUE) concerns migration and does not replace the global requirement. After completion, remaining prior locks in that scope cannot be reclaimed; new locking requests may still receive NFS4ERR_GRACE while server-wide grace continues. [1] [2]

Reclaim does not replay lost file contents or restore a backup. Data stability and write-verifier recovery remain separate concerns; a v3 COMMIT trace is not a v4.1 state-recovery procedure. [1]

Relations

related

nfs-storage, nfs-grace-period, nfs-lease, nfs-stateid, nfs-commit

Limitations

• A rejected reclaim is not proof that the original lock still excludes other clients. [1, 2]

Citations

1. RFC 8881 (NFSv4.1), section 8.4.2.1, State Reclaim. (accessed 2026-10-18)
2. RFC 8881 (NFSv4.1), section 18.51.3, RECLAIM_COMPLETE description. (accessed 2026-10-18)

Further reading

3. NFS stable writes: what COMMIT, flush and FUA actually promise (accessed 2026-10-18)

JSON: /data/terms/nfs-state-reclaim.json