Administrator Guide

Scenario System Status Data Integrity Comments
the cache to disk (Storage
Center or nonvolatile internal
storage)
Simultaneous dual-NAS
controller failure in single NAS
appliance cluster
Unavailable Lose data in cache Data that has not been written
to disk is lost
Sequential dual‑NAS controller
failure in multiple NAS
appliance cluster, same NAS
appliance
Unavailable Unaected Sequential failure assumes
enough time is available
between NAS controller
failures to write all data from
the cache to disk (Storage
Center or nonvolatile internal
storage)
Simultaneous dual‑NAS
controller failure in multiple
NAS appliance cluster, same
NAS appliance
Unavailable Lose data in cache Data that has not been written
to disk is lost
Dual‑NAS controller failure in
multiple NAS appliance cluster,
separate NAS appliances
Available, degraded Unaected
• Peer NAS controller enters
journaling mode
• Failed NAS controller can
be replaced while keeping
the le system online
FS8x00 Scale-Out NAS with FluidFS Overview
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