hesela.devHot spare
A hot spare is a standby device or reserved distributed spare capacity available to take over a failed member's role in a redundant array or pool.
An unused spare is not an already synchronized extra member or an independent backup: replacement still requires reconstruction [2]. In ZFS, spare activation and replacement state are distinct from completed resilvering [1]. A spare shortens the wait for replacement capacity; it does not add a parity level. OpenZFS documents ZED consuming pool events to automate replacement; monitoring and reconstruction completion still need separate checks [4].
Relations
- related
- raid-rebuild, degraded-array, resilver, raid, mirroring, distributed-spare
Limitations
- Automatic activation depends on the platform's fault-management services and configuration; merely listing a spare does not prove replacement has started. [4]