ReadyDATA Replicate: Fail-Over & Fail-Back
ReadyDATA Replicate can be used to Replicate data from your primary ReadyDATA storage to secondary ReadyDATA Storage.
This can be done using cloud based Replicate (via https://readydata.netgear.com) or local Replicate. Both will work however this article will focus on local Replicate.
This article describes how to do the following:
- Run continuous Replicate from the primary ReadyDATA to the secondary ReadyDATA.
- In case of loss of access to the primary system, bring the secondary system online (fail-over).
- When the primary system is recovered, Replicate changes from the secondary system back to the primary system so that protection is restored.
- When the ReadyDATAs are back in sync, bring the primary system back online (fail-back).
- Finally, re-create the Replicate job from primary to secondary so that protection is restored.
In this example, we have a share with NFS access enabled on the primary ReadyDATA:
A VMWare ESX host is connecting to this share and using it as an NFS datastore:
Stored on this NFS datastore is a running virtual machine.
Step 1: Enable Replicate and Exchange Certificates Between ReadyDATAs
- On each ReadyDATA go to System - Settings and verify that the Replicate service is started. In this example, we will use local Replicate. When using local Replicate, the ReadyDATAs should not be joined to the Replicate online portal (so the Username/Password field should be empty).
- On each ReadyDATA go to the Replicate tab and click on Certificates
- On the primary ReadyDATA in the Local Certificate section, click the Copy to Clipboard button. The Copy Certificate screen opens, displaying the certificate:
- Copy the string to the clipboard and press the Close button
- On the secondary ReadyDATA, click the + icon.
- The New Certificate screen displays:
- Give the certificate a name and paste the certificate into the key field. The press Add.
- Repeat the process exchanging the roles of the ReadyDATAs. Note that this exchange of certificates in each direction is a once off task.
Step 2: Create a Replicate Job from Primary to Secondary ReadyDATA
- On the primary ReadyDATA, go to Replicate - Jobs and click New Job
- Give the job a name, select the source dataset, enter the IP of the secondary system, select the corresponding certificate entry and press Connect. Then choose the volume on the secondary unit on which the dataset should be replicated to:
- Complete the remaining job configuration windows as shown below and finally, press Finish. In this example, we are mostly using default options. Note that the compression, encryption and deduplication options mentioned here are only applied during the data transfer. When the data is stored on the destination system, it will have the same characteristics as the source dataset.
- When the job configuration is completed, the job will begin doing the initial sync as shown below. Note that depending on the size of the source dataset and the bandwidth of the network connecting the two ReadyDATAs, then this initial sync may take a long time. You may wish to 'seed' the job before doing this initial sync. Please refer to the section on 'Seed or Reseed Replication' in the ReadyDATA software manual or look at this article for more info on this.
- After the initial sync is complete, then the secondary dataset will be only a few seconds behind the source dataset. As changes are happening on the primary, the blocks that are being changed are being automatically sent to the secondary system. As shown below, the secondary system is only three seconds behind the primary:
- The primary ReadyDATA is now protected through Replication to the secondary ReadyDATA.
Step 3: Fail-Over.
- Assume access to the primary ReadyDATA is lost. We want to fail-over to the secondary ReadyDATA.
- Go to the dataset on the secondary ReadyDATA, configure the NFS settings as needed and press Apply: