# cinder type-create eql1 # cinder type-create eql2 The following commands will allow you to create two volume types: eql1 and eql2:
![dell equallogic group manager screenshots dell equallogic group manager screenshots](http://13.58.122.80/wp-content/uploads/2015/01/launch-javaapp.jpg)
Later on, when you create a volume, you can use the volume type to specify which back end the Block Storage service should use for creating the volume. Next, declare a volume type for each back end. # openstack-config -set /etc/cinder/nf DEFAULT enabled_backends backend1,backend2 For example, to set backend1 and backend2 (from Section 3.1, “Define Each Back End”) as your back ends, run:
![dell equallogic group manager screenshots dell equallogic group manager screenshots](http://13.58.122.80/wp-content/uploads/2015/01/prepgroup.jpg)
To do so, set the defined back ends as a comma-delimited list to the enabled_backends setting in the section of /etc/cinder/nf. We can see that it takes 2 pings to failover between switches and the iSCSI portal ip address is impacted only when the Group Lead is.After defining each back end, configure the volume service to use each of them. Shutdown port on the switch for Member 2 eth0 Shutdown port on the switch for Member 1 (GL) eth0 As we have 2 blade switches I will shutdown the active controller port on the correspondent switch to see how many pings it takes to failover from Switch B1 to Switch B2: Now lets see test the switching connectivity failover. So, we can see that there is a 8 pings lost on the iSCSI portal ip address when the controller failover is the member acting as Group Lead, although it takes only 3 pings to failover from controller on each member. Now, let’s failover the active controller on Member 2 (Not GL) Let’s failover the active controller on Member 1 (GL) and see what happens: So as there is 2 members on the group, 1 has to be Group Lead (GL), in this case was the Member 1. These arrays are connected to 2 x Blade Powerconnect 10Gb switches on the Fabric Bīoth PS are in the same EqualLogic group with firmware 7.1.4. The load on the array is low as there is only 2 host mapped, this should also be taken into account. I have a Dell M1000e chassis with 2 EqualLogic PS M4110. Well, first lets talk about the environment that I have right now. Now the fun part, what happens when there is a failure? You can see which one is Active in the Group Manager interface, clicking the array under Members and then click on the Controllers tab. One controller is Active and the other is Secondary, waiting to take the control of the i/o load. Most people get an array with 2 controllers to have redundancy. So basically, you can have 2 configurations, single or dual controller.
![dell equallogic group manager screenshots dell equallogic group manager screenshots](http://4.bp.blogspot.com/-c0aSS6UEHo4/UPG1sCFWhXI/AAAAAAAAC1Y/a8LzOtiiab8/s1600/deqlall05.png)
![dell equallogic group manager screenshots dell equallogic group manager screenshots](https://i1.rgstatic.net/publication/343453189_Storage_Infrastructure_and_Solutions_Engineering_Dell_EqualLogic_Best_Practices_Series_Best_Practices_for_Oracle_11g_Backup_and_Recovery_using_Oracle_Recovery_Manager_RMAN_and_Dell_EqualLogic_Snapshot/links/5f2b4da492851cd302dfa22f/largepreview.png)
I/O should continue if you connect cables to the newly active control module. In a dual control module array, if the active control module fails, the secondary control module becomes active and begins serving I/O (called control module failover).In a single control module array, if the control module fails, the member is offline.On startup, either control module can be designated active or secondary, regardless of its previous status.Under normal operation, the status of a control module (active or secondary) does not change unless you restart the member. In a dual control module array, the other control module is secondary (mirrors cache data from the active control module). One control module is designated as active (responsible for serving I/O to the member). So lets start to see what it says the official documentation:Įquallogic PS Online Help Monitor Control ModulesĮach group member has one or two control modules installed. Hi everyone! Allways people ask me how does EqualLogic controllers work, and what they do in case of a failure.