Dell PowerFlex Appliance with PowerFlex 3.x Administration Guide

Determining and switching the MDM

Use this procedure to switch the MDM.

1. Log in to PowerFlex Manager, to determine the primary MDM.
2. To view the details of a service, select the component. Scroll down on the Service Details page, the following information is displayed based on the resource types in the service:

   Section

   Description

   Physical Nodes

   View the following information about the nodes that are part of the service: Health Asset/Service Tag iDRAC Management IP Hostname PowerFlex Mode The mode for each node is one of the following: Hyper-converged includes both SDS and SDC components. Storage Only includes only the SDS component. Compute Only includes only the SDC component. Associated IPs MDM Role The MDM role is the metadata manager role. The MDM role applies only to those nodes that part of a PowerFlex cluster. The MDM role is one of the following: Primary: The MDM in the cluster that controls the SDSs and SDCs. The primary MDM contains and updates the MDM repository, the database that stores the SDS configuration, and how data is distributed between the SDSs. This repository is constantly replicated to the secondary MDMs, so they can take over with no delay. Every PowerFlex cluster has one primary MDM. Secondary: An MDM in the cluster that is ready to take over the primary MDM role if necessary. Tie Breaker: An MDM whose sole role is to help determine which MDM is the primary. Standby MDM: A standby MDM can be called on to assume the position of a manager MDM when it is promoted to be a cluster member. Standby Tie Breaker: A standby node that is prepared to take over as a tiebreaker. Fault Set: A logical group of SDSs within a protection domain that defines by the way it is grouped where the copies of data exist.

3. Access the primary MDM:
   1. In a hyperconverged deployment, use SSH to connect to the SVM that is acting as primary MDM.
   2. In a two-layer deployment, connect to the PowerFlex storage-only node that is acting as primary MDM using SSH.
4. From the PowerFlex CLI, type the following:
   1. Type scli --login --username admin --password MDM_password to connect to the source node.
   2. Type scli --query_cluster to reverify the primary MDM.
   3. Type scli --switch_mdm_ownership to switch the primary MDM to the secondary MDM.
   4. Type scli --query_cluster to reverify the primary MDM.
5. Connect to the new SVM that is acting as primary MDM using SSH.
   1. Type scli --query_all_sds and verify that all servers are connected.
   2. Type scli --query_all_sdc and verify that all servers are connected.
6. Run inventory on PowerFlex Manager to update PowerFlex gateway with location of the new primary MDM.
   1. On the menu bar, click Resources.
   2. On the Resources page, click the All Resources tab.
   3. From the list of resources, click PowerFlex Gateway, and then click Run Inventory.

      The resource state changes to Pending. When the inventory is complete, the resource state changes to Available.