Migrating databases

Varc’s Migration tool moves keys between saved Redis or Valkey connections. It is a first-class tool in the Move section of the Dock, with three guided modes:

• Copy now copies the current database directly to another saved profile.
• Create offline bundle writes the current database to a .varcmigrate file.
• Restore Varc bundle restores a .varcmigrate file into the current database.

Standalone, Sentinel, and Cluster connections are supported. A Cluster destination always uses database 0.

Copy now

1. Connect to the source profile and open Move → Migration.
2. Choose Copy now, then choose a saved destination profile.
3. Select what to do when a key already exists: stop, skip it, or replace it.
4. Choose Review migration. Read the sampled key count, conflict estimate, compatibility findings, and any clock-skew warning.
5. Confirm the review and choose Start migration.

The source key browser stays on the left. The read-only destination browser on the right refreshes in bounded windows as migrated keys arrive, so even a very large keyspace is never loaded into renderer memory. Progress and the final report distinguish migrated, skipped, expired, failed, retried, and verified keys. Per-key problems are fetched in pages.

Create an offline bundle

Choose Create offline bundle, select the output file, and review the export. Varc writes independently compressed, integrity-checked chunks to a private partial file and atomically publishes the completed bundle.

A .varcmigrate file contains raw database values. It is portable and integrity-checked, but it is not promised to be encrypted. Store and transfer it with the same care as a database backup. Varc requires you to acknowledge this before export.

Restore a bundle

Connect to the destination profile, choose Restore Varc bundle, and select the file. Varc verifies the bundle before showing the review. Restore can resume after the last fully completed chunk; a corrupt or truncated bundle is rejected before it can be treated as complete.

Safety and limits

• This is a one-shot copy, not replication. Redis SCAN does not provide a stable snapshot while writes continue, so the report always states that concurrent-write drift is possible. Freeze source writes yourself when you need an application-consistent cutover.
• Varc never rolls back keys already copied. Cancelling or stopping produces an honest partial result.
• Raw Redis and Valkey DUMP formats are not assumed compatible. Cross-engine jobs stop at preflight in this release; use the same engine on both sides.
• Absolute expiry time is preserved by default. Review clock-skew warnings, because the destination server’s clock governs actual expiry.
• Personal accepts at most 500 destination writes per migration and refuses before write 501. Pro and Team remove that product cap; independent safety bounds still apply.
• One migration runs at a time. Jobs belong to the app process, survive a renderer reload, and appear on the dashboard so you can reopen them. Quitting Varc cancels and joins an active job.

Every job ends once as completed, completed with warnings, cancelled, failed, or indeterminate. Indeterminate means a write may have reached the destination without an acknowledgement; Varc does not blindly retry it.