SnapMirror® has been used by NetApp customers for years to replicate data efficiently between their on-premises storage appliances, and now with Cloud Volumes ONTAP, this NetApp replication capability exists for cloud-based architectures. This can do a great deal to simplify complex deployments, such as complete Azure migrations, synchronizing data between different Azure regions, or the rollout of an Azure disaster recovery copy.
How does this kind of functionality perform when using the Azure cloud and for Azure data replication? In this article, we will examine how NetApp SnapMirror and Azure storage work together to replicate your data.
Cloud Volumes ONTAP uses Azure Virtual Machines and Azure Disk Storage resources to create an Azure cloud-based virtual storage appliance. Just as on-premises systems were used in the past, an instance of Cloud Volumes ONTAP can act as either the destination or as the source when in a SnapMirror relationship. Data can be synchronized from on-premises storage into the cloud, from the cloud to on-prem, or back and forth across Azure cloud regions or between different cloud providers, all the while updating incrementally for data synchronization. SnapMirror’s functionality and easy integration with other ONTAP and Cloud Volumes ONTAP features give it flexibility and range as an effective data replication solution.
In the first step, a baseline synchronization is performed by transmitting a complete copy of a source-volume snapshot to the destination.
For data changes that take place at the source volume, SnapMirror creates a new snapshot and compares it to the baseline version. Should this process discover any blocks that have been changed, those blocks are replicated over to the destination. This newer snapshot is then considered the newest common snapshot, or in other words, the current baseline. This sync process repeats, sending incremental updates over to the destination.
In SnapMirror relationships, the volume designated as the destination remains available in an online read-only state. Instead of working with storage on the file level or otherwise, SnapMirror accesses physical blocks, meaning the destination replica is an identical copy of source volume, including all of its contents and settings. When using Cloud Volumes ONTAP’s data deduplication and data compression storage efficiencies, those optimizations will also be in place in the replica.
Should the SnapMirror relationship be broken, the destination volume will then become writable and could be utilized in a failover when synchronizing data to a DR site via SnapMirror. Because of the level of efficiency that SnapMirror has, any changes in the data that take place in the failover environment can be synced back to the primary environment when it comes online again. At that point, it would be possible to return to the original SnapMirror relationship.
Integrating SnapCenter® and SnapMirror makes it possible to replicate application-consistent snapshots. Snapshots that are application consistent can be used as a database replication technique for backing up databases. By taking advantage of the underlying storage, the creation of these application-consistent snapshots is coordinated with the application; this guarantees that there are no inconsistencies created in the snapshot by in-flight I/O operations. Once the application-consistent snapshot has been taken, SnapCenter activates SnapMirror to carry out syncs in all destination volumes based on the snapshot.
Users can create new SnapMirror relationships by using the Cloud Manager, NetApp’s UI for controlling and managing Cloud Volumes ONTAP. All that users have to do to trigger the relationship creation process in the graphical interface is drag & drop the source system to the target destination. This launches the wizard that will lead on from here.
Next, the wizard prompts the user to choose a source volume and a destination volume between which to create a new SnapMirror relationship. There are other options that can be specified here, one of which is setting the maximum transfer rate, which gives Azure users control over the amount of network bandwidth that the sync operation will use. Users will also be required to select a schedule for syncs to be carried out. This setting can also include making a single copy by choosing “One-time copy.”
In the last step, the interface will ask that the user review the setup that has been requested and to confirm in order to proceed with creating the relationship. After the relationship is created, the dashboard can be used to monitor the data transfer and replication statuses. And with that step, your Azure storage replication should be ready to go.
Below are a few of the main reasons why Azure users should use SnapMirror for Azure storage replication.
Whether migrating applications to Microsoft Azure in a big lift and shift migration or setting up an Azure storage replication to establish a new DR environment, Azure users can get more when it comes to moving data to the places you need it the most with SnapMirror and Cloud Volumes ONTAP.