nfs-grace-period · shipping · also NFS grace period

NFSv4 grace period

An NFSv4 grace period is a server recovery interval that protects the reclamation of previously held locking state from conflicting new access.

After loss of locking state, NFSv4.1 permits eligible clients to reclaim prior opens and locks. Requests that could conflict with reclaim receive NFS4ERR_GRACE; the server may allow operations when it can establish they are safe. Grace is therefore not necessarily a complete I/O outage. [1]

RECLAIM_COMPLETE ends the issuing client's reclaim opportunity for the indicated scope, not the server's grace period for all clients. Recovered locks say nothing about whether uncommitted file bytes survived. [2]

Relations

related

nfs-storage, nfs-lease, nfs-state-reclaim

Limitations

• Do not assume a universal duration or retry every NFS error as grace. [1]

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-grace-period.json