Clustering Considerations For Networking - Oracle ZFS Storage Appliance Administration Manual

Shutting Down a Clustered Configuration (CLI)
Variable
I/O latency
Storage flexibility
Network connectivity
Related Topics
"Shutting Down a Clustered Configuration (CLI)" on page 199
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Clustering Considerations for Networking

Network device, datalink, and interface failures do not cause a clustered subsystem controller to
fail. To protect against network failures inside or outside of the appliance, IPMP and/or LACP
214 Oracle ZFS Storage Appliance Administration Guide, Release OS8.6.x • September 2016
Single controller pool ownership
Internal read cache is not available
during a failback or takeover
operation, which can significantly
increase latencies for read-heavy
workloads that fit into available read
cache. Latency of write operations is
unaffected.
With external read cache
configurations (EL2ARC), read
performance is unaffected. Read
cache is shared between cluster
peers during a failback or takeover
operation, resulting in no read
latency.
All available physical storage can be
used by shares and LUNs.
All network devices in each
controller can be used while that
controller is providing service.
Multiple pools owned by different
controllers
Internal read cache is not available
during a failback or takeover
operation, which can significantly
increase latencies for read-heavy
workloads that fit into available read
cache. Latency of both read and
write operations may be increased
due to greater contention for
controller resources. This is caused
by running two workloads on the
surviving controller instead of the
usual one. When nominal workloads
on each controller approach the
controller's maximum capabilities,
latencies in the failed-over state may
be extremely high.
With external read cache
configurations (EL2ARC), read
performance is unaffected. Read
cache is shared between cluster
peers during a failback or takeover
operation, resulting in no read
latency.
Only the storage allocated to a
particular pool can be used by that
pool's shares and LUNs. Storage is
not shared across pools, so if one
pool fills up while the other has free
space, some storage may be wasted.
Only half of all network devices
in each controller can be used
while that controller is providing
service. Therefore each pool can
be connected to only half as many
physically disjoint networks.