9.5 HP P4000 Multi-Site HA/DR Solution User Guide (AX696-96074, September 2011)

In addition to setting up the Multi-Site clusters for data replication, it is important to set up the SAN
managers for quorum correctly to ensure that in the event of a failure the system can be properly
recovered. Maintaining quorum can be either an automated process or manually recovered by an
Administrator. Table 2 (page 7) summarizes common Multi-Site SAN and manager configurations.
Table 2 Common configurations of Multi-Site SANs and mangers
Site typesFailover ManagerTotal number of
managers of all types
Cluster/site setupNumber of sites
All sites are peer.In the third siteMin = three; Max =
five
Cluster spans two sitesthree physical sites
All sites are peer.In the logical third siteMin = three; Max =
five
Cluster spans two sitestwo physical sites,
with logical third site
All sites are peer.Not usedMin = three; Max =
six
Cluster spans three
sites
three physical sites
One site is designated
primary.
Not usedMin = three; Max =
five
Cluster spans two sitestwo physical sites
Best practice
In a cluster that spans multiple sites, run the same number of managers in each site. In a cluster
that spans two sites, run a Failover Manager in a third site (physical or logical) that is not included
in the cluster (“Three physical sites: cluster spans two sites, Failover Manager in third site”
(page 8)). The one exception to this rule is the two-site configuration in which one site is configured
as primary (“Two physical sites: cluster spans two sites, one site is the primary site” (page 9)). In
this case, run a majority of the managers in the primary site.
Sample configurations
The following diagrams illustrate best practice for four different configurations:
• “Three physical sites: cluster spans two sites, Failover Manager in third site” (page 8)
• “Two physical sites, logical third site: cluster spans two sites, Failover Manager in logical third
site” (page 8)
• “Three physical sites: cluster spans three sites” (page 9)
• “Two physical sites: cluster spans two sites, one site is the primary site” (page 9)
Designing a Multi-Site SAN 7