Dell PS4000 Configuration Manual

Also see for EqualLogic PS4000: Hardware Quick reference guide Hardware maintenance Instructions Installation and setup manual

Contents

Dell PS4000 Configuration Manual Manual pdf 10 page image

Dell EqualLogic Configuration Guide v11.3 5Type 9 2 x 1GbaseT1 x 10/100Mb mgtSASSATA 2nd generation PS4000 2GB Cache Small Form Factor Cannot mix SAS andSATA drives in samearrayType 10 2 x 10GB SFP+1 x 10/100Mb mgtSASSATASSD 10Gb Ethernet PS6010 – PS6510 2GB Cache Small Form FactorTable 3: Array Controller Type Comparison2.3.2 Controller RedundancyEach array can be configured with either a single controller, or dual redundant controllers. The singlecontroller configuration will provide the same level of I/O performance as a dual controllerconfiguration. The dual controller configuration provides for redundancy. Redundant controllers willprevent volume connections between hosts and SAN from being dropped in the event of an activecontroller failure.The Active Controller is the controller which is processing all disk and network I/O operations for thearray.A second controller in dual controller configurations will always be in a ―passive‖ operating mode. Inthis mode, the secondary controller will exhibit the following characteristics: Each of its Ethernet ports are electrically inactive (active lights are off) The passive controller cache mirrors the cache of the active controller.2.3.3 Controller FailoverTo support redundant controller fail over, each Ethernet port on the active controller that is connectedto the SAN must have its corresponding port on the passive controller also connected to the same SANnetwork. In the event of a controller failure, the passive controller will immediately activate andcontinue to process all data requests to the array. The following changes occur during fail over: The backup controller automatically enables each of the corresponding Ethernet ports thatwere enabled on the failed primary controller The IP addresses that were assigned to each of the failed controller Ethernet ports arereassigned to the corresponding ports on the second controller.A link failure on one or more of the Ethernet ports on the active controller does not constitute acontroller failure. For this reason, it is important to ensure that ports from each controller areconnected to at least two different switches. This will prevent a switch failure from also disabling allpaths between a host and its connected volumes.It is critical that port connections for both controllers are configured so that the corresponding portson each controller are connected to the SAN. If port 0 on the active controller is the only portconnected to the SAN, then port 0 on the passive controller must also be connected to the SAN. This isshown in the partial and fully connected controller failover scenarios illustrated in Figure 1 and Figure2 below. Note how IP addresses are reassigned to the ports during the failover process.