Guide · updated
Content Transfer Tool: sizing, top-ups and freeze planning
Code is usually what migration plans worry about; content is what decides the go-live weekend. Adobe's Content Transfer Tool (CTT) moves content from an AEM 6.3 or later instance, on-premise or AMS, to AEM as a Cloud Service, managed through Cloud Acceleration Manager.
How a transfer works
- Create a migration set in Cloud Acceleration Manager: the paths to move. A project can hold up to ten migration sets; a set expires after about 45 days without activity.
- Extraction copies the content from the source instance into a temporary cloud storage area Adobe provides.
- Ingestion loads the migration set into the target Cloud Service environment.
- Top-ups repeat both steps for changes only: extract with overwrite disabled, ingest with wipe disabled, so the delta lands on top of what is already there.
Check the limits before you plan dates
| Limit | What Adobe documents |
|---|---|
| Source version | AEM 6.3 or later. |
| Segment store | Less than 750 million JCR nodes and up to 500 GB on author; 50 GB on publish. Larger needs a support ticket with Adobe. |
| Total repository (segment + data store) | Designed for up to 20 TB with a file data store; S3 and Azure data stores can go beyond with the optional pre-copy step, which also speeds up large transfers. |
| Lucene indexes | 25 GB in total, excluding /oak:index/lucene and /oak:index/damAssetLucene. |
| Immutable paths | CTT cannot migrate content in immutable paths such as /apps; code travels through Cloud Manager. |
| MongoDB | Property values cannot exceed 16 MB; run Adobe's oak-run check before extraction. |
If you are near any limit, open the support ticket early: it is lead time you cannot compress later.
Planning the freeze
- Run the first full extraction and ingestion weeks before go-live, to stage or a dev environment, and time both steps.
- Agree with the business how long authors can stop publishing. Adobe recommends frequent differential top-ups to shorten that freeze.
- Schedule top-ups so the last one before cutover is small: daily in the final week is common.
- Fix asset validation findings from Best Practices Analyzer (missing original renditions or nodes) before the first extraction, or they travel with the content.
- Plan users and groups separately and confirm with your team how they map to Adobe IMS sign-in on Cloud Service.
On the go-live weekend
- Freeze authoring on the source.
- Run the final top-up extraction and ingestion.
- Smoke-test author and publish on Cloud Service, including recently changed pages and assets.
- Switch DNS and keep the source read-only for an agreed period.