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The steps to add an RCG in PowerFlex vary between versions 3.5+ and 4.x so each of them are covered separately.
Note: This example, which uses a single source volume, assumes the user mapped it to the ESXi hosts at the protection site and created a datastore on it. Replication is being added after that step is complete. This is not an uncommon practice, though it is also acceptable to present volumes after replication is active.
Log in to the PowerFlex GUI as a user with administrator privilege.
The target volume does not appear in the screen until the source volume is highlighted. Once selected press ADD PAIR and NEXT.
The volumes begin to synchronize. When the Consistency column moves from Partially Consistent (as shown in Figure 12) to Consistent, synchronization is complete. Since this is asynchronous replication, the remote volume is write-disabled.
After creating the RCG, present the remote volume or volumes to the ESXi hosts at the recovery site. The remote volume is mapped as a read-only device. When a test failover or actual failover is required, PowerFlex changes the access of the device to read/write automatically.
The mapping of the replicated remote volume is only possible in the RCG screen, not the Volumes screen. Any attempt to map in the Volumes screen results in the message in Figure 13.
Note: Although Dell Technologies recommends using read-only for access, using a setting of no_access also works.
Go to the RCGs menu on the left-hand side, check the box next to the appropriate RCG in the screen on the right and select Map from the MAPPING drop-down menu as shown in Figure 14.
Next, select the checkbox next to the ESXi hosts in the recovery site, and click MAP. Ensure that the Access Mode is set to Read Only (default). Then click APPLY. This is shown in Figure 15.
Log in to the PowerFlex Manager GUI as a user with administrator privilege.
If Manual Provisioning is chosen as shown in Figure 21, select the volume from the Source column and then select a volume of the same size from the Target column and select Add Pair and then click Next. This is similar to PowerFlex 3.
Similarly, for Manual Provisioning as shown in Figure 23, select Add and Activate.
After creating the RCG, present the remote volume to the ESXi hosts at the recovery site. The remote volume is mapped as a read-only device. When a test failover or actual failover is required, PowerFlex changes the access of the device.
Because of a change in the PowerFlex Manager GUI in PowerFlex 4.0, the mapping of the replicated remote volume is not possible in the RCG screen as there is no mapping menu. The volume must be mapped through the command line interface (CLI). To do this, login to the scli interface as the admin user. Query for the existing replication pairs by running scli –query_all_replication_pairs, and then map the volume read-only to the ESXi host(s) with scli –map_volume_to_host. If there are multiple ESXi hosts, the flag allow_multiple_hosts is required. An example is shown in Figure 25.
Once the volume is mapped, the PowerFlex environment setup is ready for SRM integration.
Although it is not possible to map a volume at the target site during the initial RCG creation, the feature is available for additional pairs. Take the following steps to add and map an additional volume pair to an existing RCG.
In the screen shown in Figure 27, select the volume, the host, and then choose Map before clicking Next.
The pair is now added to the RCG and mapped to the target host, making it available for use with SRM.
Note: It is possible for the user to create an RCG using scli that contains no pairs, and then add all pairs using the wizard which permits the mapping. This avoids having to map the first volume using scli though CLI is necessary using either method because the GUI does not permit the creation of an empty RCG.
In PowerFlex 4.5, the ability to map the target volumes read-only is re-enabled in the UI. The wizard proceeds like PowerFlex version 3.
Figure 29: Mapping target volume read-only in PowerFlex 4.5 – Step 1
2. Highlight the volume(s) and use the double-arrow to move them to the right-hand side of the panel. Then click Next as shown in Figure 30.
Figure 30. Mapping target volume read-only in PowerFlex 4.5 – Step 2
3. Check the box next to the host(s) at the target site and use the double arrows to move it to the right-hand side of the panel. Then click Next as shown in Figure 31.
Figure 31. Mapping target volume read-only in PowerFlex 4.5 – Step 3
4. Use the check box to select the volume(s) and select Read Access from the options at the top. Then click Finish. A warning box appears. The user should select Map RCG Target Volumes. Both the step and warning box are shown in Figure 32.
Figure 32. Mapping target volume read-only in PowerFlex 4.5 – Step 4
Once the volume is mapped, the PowerFlex environment setup is ready for SRM integration.