Cisco Cisco Prime Network 3.8 Folheto
White Paper
© 2009 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information.
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Server Connectivity
Figure 4. Connections between the Primary and Secondary
Cluster heartbeat is facilitated using redundant interfaces through direct connect crossover (reversing) Ethernet
cables. If the connection between the servers fails, the heartbeat can also be sent across the LAN. Heartbeat
messages run across a low latency transport (LLT) protocol, providing the high-speed, low-latency mechanism that
Veritas uses for both local and geographical redundancies to help ensure that all nodes get status update
information at the same time.
If using IP Multipathing (IPMP), the server’s interfaces can be made available and plumbed up through the OS,
requiring less VCS administration. VCS is used to assign a logical IP address to the dual-node cluster. All ANA
clients (GUI and northbound interface), all units, and the Oracle application will use the logical IP address. In this
way, failover can occur rapidly with the server’s IP address being totally transparent.
Internal and External Storage
High availability local redundancy requires both internal and external storage for the two gateways. Internally, each
gateway must contain at least two disks (the root “/” disks) containing the operating system plus Veritas. Those disks
are mirrored (RAID 1) using Veritas Volume Manager. If both the primary and secondary gateways are equipped with
four disks instead of two, a more reliable RAID 1+0 configuration can be used. (Note: The 1+0 configuration is
mirrored sets in a striped set, different from 0+1, striped sets in a mirrored set.)
Externally, the Cisco ANA High Availability mechanism requires a single external storage unit containing a set of
mirrored disks. If the disk array has RAID controllers (usually, it does), Veritas Volume Manager is only used to
create one or more logical volumes since mirroring and striping are automatically done by the controller at a lower
level. Multiple RAID configurations are possible, depending on the level of availability the customer wants to
implement. Two suggested options are: RAID 5+0 (mirroring/parity + striping), using three or five disks, or RAID 1+0
(mirroring + striping), using two or four disks.