OCI Object Storage cross-region replication for DR

#How it works

• Asynchronous, one-way replication of objects from a source bucket to a destination bucket in another region (or the same region).
• The destination bucket is read-only while it's a replication target.
• Only objects created after the policy are replicated. Copy existing objects separately (bulk copy, oci os object copy, or rclone).

#1. IAM policy for the service

Object Storage needs permission to manage objects in both regions:

Allow service objectstorage-ap-mumbai-1 to manage object-family in compartment cmp-payments-prod

(Use the service name for the source region.)

#2. Create the destination bucket

In Hyderabad, same compartment structure, versioning and encryption settings as the source. With customer-managed keys, the destination bucket uses a key in the DR region's Vault.

#3. Create the policy

oci os replication create-replication-policy --bucket-name invoices-prod \
  --name invoices-to-hyd --destination-region ap-hyderabad-1 --destination-bucket invoices-prod-dr
oci os replication list-replication-policies --bucket-name invoices-prod --output table

#4. Copy existing objects

# server-side copy, one object (no download through your machine)
oci os object copy --bucket-name invoices-prod --source-object-name 2026/10/inv-1.pdf \
  --destination-region ap-hyderabad-1 --destination-bucket invoices-prod-dr

For large buckets, script server-side copies (no download) or use rclone with the OCI backend.

#5. Monitor

oci os replication get-replication-policy shows status and time last sync. Alert when it's older than the RPO.

#6. Failover

1. Delete the replication policy (or stop it) to make the destination bucket writable.
2. Point applications at the DR bucket (namespace + bucket name in config, or a DNS/config switch).
3. After the primary region returns, set up replication in the reverse direction and copy back changes.

#Limits to remember

• Deletes of objects are replicated; this isn't a backup.
• Retention rules on the destination must be compatible with replication (check documentation before enabling both).
• Replication is asynchronous; very recent objects might not be in DR yet.

Tip

Store the DR bucket name in configuration from day one (STORAGE_BUCKET, STORAGE_REGION). Switching then becomes a config change, not a code release during an outage.