Replicating a Volume
The Block Volume service provides you with the capability to perform ongoing automatic asynchronous replication of block volumes, boot volumes, and volume groups to other regions and availability domains.
There are two types of replication:
- Cross region, for replication between regions.
- Cross availability domain, for replication between availability domains within the same region.
This feature supports the following scenarios without requiring volume backups and volume group backups:
- Disaster recovery
- Migration
- Business expansion
The replication feature is complementary to the backup feature, not a replacement. Backups give you a point-in-time snapshot of volumes that enables you to return to a previous version of a volume or volume group. Replicas give you the current version of the data.
When you enable replication for a volume or volume group, the process includes an initial sync of the data from the source to the replica. Depending on volume size and amount of data written to volumes, this sync can take hours. After the initial synchronization process is complete, the replication process is continuous, with the typical Recovery Point Object (RPO) target rate being less than thirty minutes for replication across regions, however the RPO can vary. See Limitations and Considerations.
Replication does not cause any downtime or impact on source volumes.
Limitations and Considerations
The following applies to both replication to another region and replication to another availability domain within the same region.
- Replication is not supported for volumes encrypted using customer-managed Vault encryption keys.
- You cannot resize a volume with replication enabled. When resizing a volume, you need to disable replication, which deletes the volume replica. After the volume is resized, you can reenable replication for the volume, which starts the replication process from scratch.
- While the typical RPO target rate is significantly less than thirty minutes for replication, the RPO can vary depending on the change rate of data on the source volume. For example, the RPO can be greater than an hour for volumes with a large amount of write I/O operations to the volume.
Cost Considerations for Replication
After you enable replication for a volume or volume group, it will be replicated in the specified availability domain or the specified region and availability domain. Your bill will include storage costs for the volume or volume group replica in the destination. The replica in the destination is billed using the Block Storage Lower Cost option price, regardless of volume type in the source region.
See Oracle Storage Cloud Pricing for information about storage pricing.
For cross region replication, your bill will also include applicable network costs, see Network Costs for Cross Region Replication.
Cross Region Replication
Block Volume replication supports replicating a volume or volume group to another region. For this type of replication, when you enable replication for a volume or volume group, you select a different region than the current source region as the destination region to replicate to. If the destination region supports multiple availaiblity domains, you can also select the availability domain you want to replicate to.
The source region for the volume or volume group determines the target regions available to select as a destination region for replication. Each region has one or more regions available as possible destination regions. The destination regions are selected based on geographical locations. Your tenancy must be subscribed to the destination region for replication. See Source and Destination Region Mappings for more information.
Network Costs for Cross Region Replication
Your bill will also include any applicable network costs for the replication process between regions. Network costs for replication between availability domains within the same region are not billed. As part of the replication process, all data being updated on the source volume or source volume group is transferred to the replica, so volumes with continual updates incur higher network costs.
You can see the amount of data transferred for an individual volume during replication in the Console.
To see the amount of data transferred from the replication process for a volume
- Open the navigation menu and click Storage. Under Block Storage, click Block Volumes.
- Click the replica that you want to see the amount of data transferred for. On the Replica Details page, the Total Data Transferred field displays the amount of data, in GBs, that has been transferred during the replication process for the volume. This number includes all data from the point that volume replication was enabled to now.
See Oracle Networking Cloud Pricing for information about network pricing.
Source and Destination Region Mappings
If your tenancy is not subscribed to any of the destination regions for the source region, and the source region only supports one availability domain, no regions are displayed in the region list and an error message is shown. For source regions containg multiple availability domains, the source region is displayed in the region list, and cross availability domain replication is the only replication available. To use cross region replication, you must subscribe to one of the destination regions for the source region. To subscribe to a region, see Managing Regions.
If you do not see a region that you are subscribed to in the destination region list, open a support ticket to request that the region be added as a destination target for the source region for your volume or volume group.
The following table lists the region mappings for cross region replication.
| Source Region | Destination Region |
|---|---|
| Australia East (Sydney) |
|
| Australia Southeast (Melbourne) |
|
| Brazil East (Sao Paulo) |
|
| Brazil Southeast (Vinhedo) |
|
| Canada Southeast (Montreal) |
|
| Canada Southeast (Toronto) |
|
| Chile Central (Santiago) |
|
| Chile West (Valparaiso) |
|
| Colombia Central (Bogota) |
|
| France Central (Paris) |
|
| France South (Marseille) |
|
| Germany Central (Frankfurt) |
|
| India South (Hyderabad) |
|
| India West (Mumbai) |
|
| Israel Central (Jerusalem) |
|
| Italy Northwest (Milan) |
|
| Japan Central (Osaka) |
|
| Japan East (Tokyo) |
|
| Mexico Central (Queretaro) |
|
| Mexico Northeast (Monterrey) |
|
| Netherlands Northwest (Amsterdam) |
|
| Saudi Arabia West (Jeddah) |
|
| Singapore (Singapore) |
|
| South Africa Central (Johannesburg) |
|
| South Korea Central (Seoul) |
|
| South Korea North (Chuncheon) |
|
| Spain Central (Madrid) |
|
| Sweden Central (Stockholm) |
|
| Switzerland North (Zurich) |
|
| UAE Central (Abu Dhabi) |
|
| UAE East (Dubai) |
|
| UK South (London) |
|
| UK West (Newport) |
|
| US East (Ashburn) |
|
| US Midwest (Chicago) |
|
| US West (Phoenix) |
|
| US West (San Jose) |
|
Cross Availability Domain Replication
Block Volume replication supports replicating a volume or volume group to another availability domain within the same region. For this type of replication, when you enable replication for a volume or volume group, if the current region contains more than one availability domain, the regions list will include the current region. Select this region as the source region, and then select the availaiblity domain that you want to replicate to.
Replication across availability domains is only supported in commercial regions with multiple availability domains. To determine which regions contain more than one availability domain, see the Availability Domains field in the table listing the commercial regions in About Regions and Availaibility Domains.
Replication Metrics
The Block Volume service emits metrics to help you track volume replication operations. For more information, see Replication Metrics and Block Volume Metrics.
Tagging Resources
You can apply tags to your resources to help you organize them according to your business needs. You can update the resource later with the desired tags. For general information about applying tags, see Resource Tags. Any tags applied to the source volume are replicated to the volume replica in the destination region.
Required IAM Policy
To use Oracle Cloud Infrastructure, you must be granted security access in a policy by an administrator. This access is required whether you're using the Console or the REST API with an SDK, CLI, or other tool. If you get a message that you don’t have permission or are unauthorized, verify with your administrator what type of access you have and which compartment to work in.
For administrators: The policy in Let volume admins manage block volumes, backups, and volume groups lets the specified group do everything with block volumes, backups, and volume groups.
Using the Console
Block Volume Replicas
Use the Console procedures in this section for block volume replicas.
Use the steps described in this procedure to enable replication on an existing volume. You can also enable replication when you create a volume, see Creating a Block Volume.
- Open the navigation menu and click Storage. Under Block Storage, click Block Volumes.
-
Click the block volume that you want to enable replication for.
Click Edit.
In the Cross Region Replication section, select ON.
For cross region replication, select the region you want to replicate the volume to, the availability domain to place the volume replica in, and then specify the name for the volume replica.
To replicate to another availability domain in the same region, select the region the volume is located in, the availability domain to place the volume replica in, and then specify the name for the volume replica.
Check CONFIRM to acknowledge the cost warning.
-
Click Save Changes.
To change the destination region or availability domain for cross region replication you need to first turn cross region replication off for a volume. Then specify the new region and availability domain selections when you turn replication on again.
- Open the navigation menu and click Storage. Under Block Storage, click Block Volumes.
-
Click the block volume that you want to change the replication settings for.
- Click Edit.
- In the Cross Region Replication section, select OFF.
- Check CONFIRM to acknowledge the that volume replica will be deleted.
-
Click Save Changes.
- Click Edit.
- In the Cross Region Replication section, select ON.
-
For cross region replication, select the region you want to replicate the volume to, the availability domain to place the volume replica in, and then specify the name for the volume replica.
To replicate to another availability domain in the same region, select the region the volume is located in, the availability domain to place the volume replica in, and then specify the name for the volume replica.
- Check CONFIRM to acknowledge the cost warning.
-
Click Save Changes.
- Open the navigation menu and click Storage. Under Block Storage, click Block Volumes.
-
Click the block volume that you want to disable replication for.
- Click Edit.
- In the Cross Region Replication section, select OFF.
- Check CONFIRM to acknowledge the that volume replica will be deleted.
-
Click Save Changes.
For volumes in a volume group configured for replication, activate the volume group replica instead of individual volume replicas if you want to ensure that all replicas are activated from the same coordinated synchronization point.
See Limitations and Considerations and To activate a volume group replica.To create a new volume from a volume replica, you need to activate the replica. The activation process creates a new volume by cloning the replica.
- Open the navigation menu and click Storage. Under Block Storage, click Block Volume Replicas. Ensure that you are in correct destination region or availability domain that contains the volume replica you want to activate.
-
Click the replica that you want to activate.
- Click Activate to open the Activate Volume Replica form.
- On the Activate Volume Replica form, specify the settings for the new volume, including:
- Name
- Compartment
- Size and performance settings
- Backup policy
- Volume replication
- Encryption
- Tags
- Click Create. The new volume will appear in the block volumes list, in the provisioning state.
The volume replica's details page provides information about the replica's status.
- Open the navigation menu and click Storage. Under Block Storage, click Block Volume Replicas. Ensure that you are in the destination region and availability domain containing the volume replica that you want to view.
-
Click the replica that you're interested in.
- The replica details page displays the following relevant fields:
- Last Sync: The time of the last data synchronization from the source volume to the replica.
- Total Data Transfered: The amount of data, in GBs, that has been transferred during the replication process for the volume. This includes all data from the point that volume replication was enabled to now.
To failback a volume replica to the source region, you need activate the volume replica in the destination region, with volume replication enabled, and select the original source region as the target region for replication.
- Open the navigation menu and click Storage. Under Block Storage, click Block Volume Replicas. Ensure that you are in correct destination region that contains the volume replica you want to activate.
-
Click the replica that you want to activate.
- Click Activate to open the Activate Volume Replica form.
- On the Activate Volume Replica, specify the settings for the new volume, including:
- Name
- Compartment
- Size and performance settings
- Backup policy
- Volume replication
- Encryption
- Tags
Ensure that Volume Replication is enabled, and select the original source region.
- Click Create. The new volume will appear in the block volumes list, in the provisioning state. Once the initial synchronization finishes, the failback process is complete, and you can use the volume in the original source region.
Boot Volume Replicas
Use the Console procedures in this section for boot volume replicas.
Use the steps described in this procedure to enable replication on an existing boot volume.
- Open the navigation menu and click Storage. Under Block Storage, click Block Volumes. In the Block Storage menu on the sidebar, click Boot Volumes.
-
Click the boot volume that you want to enable replication for.
- Click Edit.
- In the Cross Region Replication section, select ON.
-
For cross region replication, select the region you want to replicate the boot volume to, the availability domain to place the boot volume replica in, and then specify the name for the boot volume replica.
To replicate to another availability domain in the same region, select the region the boot volume is located in, the availability domain to place the boot volume replica in, and then specify the name for the boot volume replica.
- Check CONFIRM to acknowledge the cost warning.
-
Click Save Changes.
To change the destination region or availability domain for cross-region replication you need to first turn cross-region replication off for a boot volume. Then specify the new region and availability domain selections when you turn cross-region replication on again.
- Open the navigation menu and click Storage. Under Block Storage, click Block Volumes. In the Block Storage menu on the sidebar, click Boot Volumes.
-
Click the boot volume that you want to change the replication settings for.
- Click Edit.
- In the Cross Region Replication section, select OFF.
- Check CONFIRM to acknowledge the that boot volume replica will be deleted.
-
Click Save Changes.
- Click Edit.
- In the Cross Region Replication section, select ON.
-
For cross region replication, select the region you want to replicate the boot volume to, the availability domain to place the boot volume replica in, and then specify the name for the boot volume replica.
To replicate to another availability domain in the same region, select the region the boot volume is located in, the availability domain to place the boot volume replica in, and then specify the name for the boot volume replica.
- Check CONFIRM to acknowledge the cost warning.
-
Click Save Changes.
- Open the navigation menu and click Storage. Under Block Storage, click Block Volumes. In the Block Storage menu on the sidebar, click Boot Volumes.
-
Click the boot volume that you want to disable replication for.
- Click Edit.
- In the Cross Region Replication section, select OFF.
- Check CONFIRM to acknowledge the that boot volume replica will be deleted.
-
Click Save Changes.
For volumes in a volume group configured for replication, activate the volume group replica instead of individual volume replicas if you want to ensure that all replicas are activated from the same coordinated synchronization point.
See Limitations and Considerations and To activate a volume group replica.To create a new volume from a volume replica, you need to activate the replica. The activation process creates a new volume by cloning the replica.
- Open the navigation menu and click Storage. Under Block Storage, click Block Volumes. In the Block Storage menu on the sidebar, click Boot Volume Replicas. Ensure that you are in correct destination region that contains the boot volume replica you want to activate.
-
Click the boot volume replica that you want to activate.
- Click Activate to open the Activate Volume Replica form.
- On the Activate Volume Replica, specify the settings for the new volume, including:
- Name
- Compartment
- Size and performance settings
- Backup policy
- Volume replication
- Encryption
- Tags
- Click Create. The new volume will appear in the boot volumes list, in the provisioning state.
The boot volume replica's details page provides information about the replica's status.
- Open the navigation menu and click Storage. Under Block Storage, click Block Volumes. In the Block Storage menu on the sidebar, click Boot Volume Replicas. Ensure that you are in the destination region and availability domain containing the boot volume replica that you want to view.
-
Click the replica that you're interested in.
- The replica details page displays the following relevant fields:
- Last Sync: The time of the last data synchronization from the source boot volume to the replica.
- Total Data Transfered: The amount of data, in GBs, that has been transferred during the replication process for the boot volume. This includes all data from the point that cross-region replication was enabled to now.
To failback a boot volume replica to the source region, you need activate the boot volume replica in the destination region, with volume replication enabled, and select the original source region as the target region for replication.
- Open the navigation menu and click Storage. Under Block Storage, click Block Volumes. In the Block Storage menu on the sidebar, click Boot Volume Replicas. Ensure that you are in correct destination region that contains the boot volume replica you want to activate.
-
Click the replica that you want to activate.
- Click Activate to open the Activate Volume Replica form.
- On the Activate Volume Replica, specify the settings for the new boot volume, including:
- Name
- Compartment
- Size and performance settings
- Backup policy
- Volume replication
- Encryption
- Tags
Ensure that Volume Replication is enabled, and select the original source region.
- Click Create. The new boot volume will appear in the boot volumes list, in the provisioning state. Once the initial synchronization finishes, the failback process is complete, and you can use the boot volume in the original source region.
Using the CLI
For information about using the CLI, see Command Line Interface (CLI).
Block Volume Operations
Use the following operations for cross region replication of block volumes.
Open a command prompt and run:
oci bv volume create --compartment-id <compartment_ID> --block-volume-replicas '[{"displayName":"<display_name>","availabilityDomain":"<availability-domain_ID>"}]' For example:
oci bv volume create --compartment-id ocid1.compartment.oc1.phx.<unique_ID> --block-volume-replicas '[{"displayName":"Sample_Replica","availabilityDomain":"pjBI:US-ASHBURN-AD-1"}]'Open a command prompt and run:
oci bv volume update --volume-id <volume_ID> --block-volume-replicas '[{"displayName":"<display_name>","availabilityDomain":"<availability-domain_ID>"}]' For example:
oci bv volume update --volume-id ocid1.volume.oc1.phx.<unique_ID> --block-volume-replicas '[{"displayName":"Sample_Replica","availabilityDomain":"pjBI:US-ASHBURN-AD-1"}]'Open a command prompt and run:
oci bv volume update --volume-id <volume_ID> --block-volume-replicas '[]' For example:
oci bv volume update --volume-id ocid1.volume.oc1.phx.<unique_ID> --block-volume-replicas '[]'For volumes in a volume group configured for replication, activate the volume group replica instead of individual volume replicas if you want to ensure that all replicas are activated from the same coordinated synchronization point.
See Limitations and Considerations and To activate a volume group replica.Open a command prompt and run:
oci bv volume create --source-volume-replica-id <volume_ID> --compartment-id <compartment_ID> --availability-domain <availability_domain> For example:
oci bv volume create --source-volume-replica-id ocid1.blockvolumereplica.oc1.phx.<unique_ID> --compartment-id ocid1.compartment.oc1.phx.<unique_ID> --availability-domain ABbv:PHX-AD-1 Open a command prompt and run:
oci bv block-volume-replica list --availability-domain <availability_domain> --compartment-id <compartment_ID>For example:
oci bv block-volume-replica list --availability-domain ABbv:PHX-AD-1 --compartment-id ocid1.compartment.oc1.phx.<unique_ID> Open a command prompt and run:
oci bv block-volume-replica get --block-volume-replica-id <block-volume-replica-ID>For example:
oci bv block-volume-replica get --block-volume-replica-id ocid1.blockvolumereplica.oc1.phx.<unique_ID>Boot Volume Operations
Use the following operations for cross region replication of boot volumes.
Open a command prompt and run:
oci bv boot-volume create --source-boot-volume-id <volume_ID> --compartment-id <compartment_ID> --boot-volume-replicas '[{"displayName":"<display_name>","availabilityDomain":"<availability-domain_ID>"}]' For example:
oci bv boot-volume create --source-boot-volume-id ocid1.bootvolume.oc1.phx.<unique_ID> --compartment-id ocid1.compartment.oc1.phx.<unique_ID> --boot-volume-replicas '[{"displayName":"Sample_Replica","availabilityDomain":"pjBI:US-ASHBURN-AD-1"}]'Open a command prompt and run:
oci bv boot-volume update --boot-volume-id <volume_ID> --boot-volume-replicas '[{"displayName":"<display_name>","availabilityDomain":"<availability-domain_ID>"}]' For example:
oci bv boot-volume update --boot-volume-id ocid1.bootvolume.oc1.phx.<unique_ID> --boot-volume-replicas '[{"displayName":"Sample_Replica","availabilityDomain":"pjBI:US-ASHBURN-AD-1"}]'Open a command prompt and run:
oci bv boot-volume update --boot-volume-id <volume_ID> --boot-volume-replicas '[]' For example:
oci bv boot-volume update --boot-volume-id ocid1.bootvolume.oc1.phx.<unique_ID> --boot-volume-replicas '[]'For volumes in a volume group configured for replication, activate the volume group replica instead of individual volume replicas if you want to ensure that all replicas are activated from the same coordinated synchronization point.
See Limitations and Considerations and To activate a volume group replica.Open a command prompt and run:
oci bv boot-volume create --source-volume-replica-id <volume_ID> --compartment-id <compartment_ID> --availability-domain <availability_domain> For example:
oci bv boot-volume create --source-volume-replica-id ocid1.bootvolumereplica.oc1.phx.<unique_ID> --compartment-id ocid1.compartment.oc1.phx.<unique_ID> --availability-domain ABbv:PHX-AD-1 Open a command prompt and run:
oci bv boot-volume-replica list --availability-domain <availability_domain> --compartment-id <compartment_ID>For example:
oci bv boot-volume-replica list --availability-domain ABbv:PHX-AD-1 --compartment-id ocid1.compartment.oc1.phx.<unique_ID> Open a command prompt and run:
oci bv boot-volume-replica get --boot-volume-replica-id <boot-volume-replica-ID>For example:
oci bv boot-volume-replica get --boot-volume-replica-id ocid1.bootvolumereplica.oc1.phx.<unique_ID>Using the API
For information about using the API and signing requests, see REST API documentation and Security Credentials. For information about SDKs, see SDKs and the CLI.
Use the following operations to list and retrieve volume replicas:
- ListBlockVolumeReplicas
- GetBlockVolumeReplica
- ListBootVolumeReplicas
- GetBootVolumeReplica
- ListVolumeGroupReplicas
- GetVolumeGroupReplica
You can enable replication for a boot volume or block volume when you create or update a volume. To disable replication, use the Update operation. To activate a volume replica, use the Create operation and pass the source volume's replica ID.
For volumes in a volume group configured for replication, use CreateVolumeGroup to activate replicas instead of CreateVolume or CreateBootVolume if you want to ensure that all replicas are activated from the same coordinated synchronization point. See Limitations and Considerations.