Technical information

55 EqualLogic Configuration Guide | Version 15.2 | August 2014
9.7 Vertical port failover behavior in PS6210 controllers
In PS Series controllers prior to PS4110/6110/6210 families, a link failure or a switch failure was not
recognized as a failure mode by the controller. This caused a failure of a link or an entire switch to reduce
bandwidth available from the array. Referring to Figure 13, assume that CM0 is the active controller. In
vertical port failover, if CM0 senses a link drop on the local ETH0 port connection path, it will
automatically begin using the ETH0 port on the backup controller (CM1). Vertical port failover is bi-
directional. If CM1 is the active controller then vertical port failover will occur from CM1 ports to CM0
ports if necessary.
Figure 18 PS6210 vertical port failover
For more information about vertical port failover, see the PS6210 Hardware Owner’s Manual at
https://eqlsupport.dell.com/support/download.aspx (requires support login). With the PS6210 family of
controllers, vertical port failover can ensure continuous full bandwidth is available from the array even if
you have a link or switch failure. This is accomplished by combining eacth 10GbE “eth0” and “eth1” ports in
each controller into a single logical port from the point of view of the active controller. In a fully redundant
SAN configuration, you must configure the connection as shown in Figure 18.
In a redundant switch SAN configuration, to optimize the system response in the event you have a vertical
port failover you must connect either the SFP+ cable or the 10GbaseT cable from each controller to a
different switch in the SAN network. While it is a supported configuration, it is not recommended to
connect both the SFP+ and 10GbaseT ports on each controller at the same time. In this scenario, the SFP+
port will always be the preferred active port and this preference cannot be changed by the user. This
preference is not guaranteed in future array firmware releases.
The connection paths illustrated in Figure 18 show how to connect the port connection paths between
the two controllers. Also note how IP addresses are assigned to the vertical port pair.