Cisco MDS 9000 series Configuration Manual page 49

Chapter 3 Deployment Considerations
S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
• IOA uses the image that is bundled as a part of the Cisco MDS NX-OS Release. In Cisco MDS
NX-OS Release 4.2(1), SSI images are not supported for IOA.
• IOA decides the master based on a master election algorithm. If you have multiple switches in the
IOA cluster, you must add all the switches in the site that you manage from into the cluster before
adding switches from the remote site. For more information see
and Recovery Scenarios."
IOA clustering framework uses IP connectivity for its internal operation. In Cisco NX-OS Release
•
4.2(1), if an IOA cluster becomes nonoperational due to IP connectivity, IOA flows are brought
down to offline state. In this state, the hosts may not be able to see the targets. To accelerate the IOA
flows, the IOA cluster must be operational and there must be at least one IOA switch in each site
that is online within this IOA cluster.
• The targets must be connected to a FC-Redirect-capable switch running Cisco MDS NX-OS Release
4.2(1) or later. The hosts must be connected to a FC-Redirect-capable switch running Cisco MDS
SAN-OS Release 3.3(1c) or later.
In Cisco MDS NX-OS Release 4.2(1), the following features cannot coexist with IOA for a specific
•
flow: SME, DMM, IVR, NPV and NPIV, F PortChannel or Trunk. In Cisco NX-OS Release 5.0(1),
IVR is supported with IOA.
To implement IOA on IVR flows, the host switches, target switches, border switches, and the IOA
•
switches must all be running AAM-supported Cisco MDS NX-OS Release 5.0(1) or later. For more
information, refer to the Cisco MDS 9000 Family NX-OS Inter-VSAN Routing Configuration Guide.
• If there are multiple Cisco IOA clusters in a region, a target can be part of the IOA configuration in
only one cluster. To change the target to a different cluster, the configuration in the first cluster must
be deleted before creating the configuration in the second cluster.
• IOA licenses are not tied to a specific IOA service engine. IOA licenses are checked out when any
of the following event occurs:
• If IOA flows are configured and a copy running to startup is not performed, FCR rules are removed
automatically for these flows in all VSANs except VSAN 1. VSAN 1 is a default VSAN that is
always persistent even without a copy running to startup and so, FCR rules are preserved for this
VSAN. To recover from this, you can execute "clear fc-redirect decommision-switch" prior to the
reboot of the switch to purge the FCR configs in VSAN 1. Alternately, you can cleanup the entire
IOA flow configuration prior to the reboot of the switch.
• If an MDS switch is connected through an ISL using a twinpeak line card and the targets are
connected to the MDS switch, then this MDS switch can connect to a maximum of 160 targets. This
because the maximum number of ELS entries on the twinpeak line card is 320 entries. For example,
in an IOA configuration that has 5 flows (1 host : 1 target) you can have 10 ELS entries on a module
with ISL and in a IOA configuration that has 10 flows (2 hosts : 1 target), you can have only 10 ELS
entries. This because ELS entries depends on the number of targets.
The workaround for such a case would be to implement allowed VSAN on ISL. For example, if
OL-20708-01, Cisco MDS NX-OS Release 5.0(1a)
If one of the service engines runs IOA or FCIP, you can configure other service engines to run
–
either FCIP or IOA.
An IOA interface is configured.
–
A line card that contains the IOA interface comes online. There are no links between an IOA
–
license and a IOA service engine. If a line card goes offline, another IOA interface can be
brought up using the same IOA license. In such cases, when the line card comes back online,
the IOA interface is automatically brought down with status displaying No License. You need
to to install licenses corresponding to the number of IOA interfaces configured regardless of the
status of the line card.
Appendix B, "Cluster Management
Cisco MDS 9000 Family I/O Accelerator Configuration Guide
Limitations and Restrictions
3-9