About Omneon MediaGrid - Harmonic Inc

Configuring a Stretch Cluster
System Installation with ContentServer 3000 Series
MediaGrid now supports using replication on systems with the ContentServer 3000 series. This
feature provides an additional level of data protection by allowing you to set up a ContentServer 3000
system across two different sites and replicate data across sites. This configuration is known as a
“stretch cluster.” In the event of a site failure at one site, replication ensures that the data will be
available at the second site.
Note the following:
• Because of the added redundancy in a stretch cluster storage capacity will be reduced. Make sure
to work with your Harmonic representative to size your system appropriately. Also, note that
although this configuration results in faster read operations, write operations are slowed.
• The two sites in a stretch cluster must be no more than 500 meters apart.
• Each ContentDirector in your system must have a fiber optic network card installed. For
assistance, contact your Harmonic representative.
• Systems must be configured with two groups, one for each site.
• Each group in the cluster must have the same amount of storage with the exact same combination
of ContentServers and ContentStores.
• The replication factor for the cluster must be set at 2.
Figure 19 shows a sample stretch cluster using the ContentServer 3000 system with 1 GbE NIC
cards. Figure 20 shows a shows a sample stretch cluster using the ContentServer 3000 system with 10
GbE NIC cards.
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