---
title: "POST /v1/projects/{project}/instances/{instance}/startExternalSync"
method: POST
path: "/v1/projects/{project}/instances/{instance}/startExternalSync"
tags: ["projects"]
---

# POST /v1/projects/{project}/instances/{instance}/startExternalSync

`POST /v1/projects/{project}/instances/{instance}/startExternalSync`

Start External primary instance migration.

## Path parameters

- `project` string, required
- `instance` string, required

## Request body

- SqlInstancesStartExternalSyncRequest — Instance start external sync request.
  - `replicaOverwriteEnabled` boolean — Optional. MySQL only. True if end-user has confirmed that this SES call will wipe replica databases overlapping with the proposed selected_objects. If this field is not set and there are both overlapping and additional databases proposed, an error will be returned.
  - `syncMode` 'EXTERNAL_SYNC_MODE_UNSPECIFIED' | 'ONLINE' | 'OFFLINE' — External sync mode.
  - `mysqlSyncConfig` MySqlSyncConfig — MySQL-specific external server sync settings.
    - `initialSyncFlags` SyncFlags[] — Flags to use for the initial dump.
      - `name` string — The name of the flag.
      - `value` string — The value of the flag. This field must be omitted if the flag doesn't take a value.
  - `skipVerification` boolean — Whether to skip the verification step (VESS).
  - `migrationType` 'MIGRATION_TYPE_UNSPECIFIED' | 'LOGICAL' | 'PHYSICAL' — Optional. MigrationType configures the migration to use physical files or logical dump files. If not set, then the logical dump file configuration is used. Valid values are `LOGICAL` or `PHYSICAL`. Only applicable to MySQL.
  - `syncParallelLevel` 'EXTERNAL_SYNC_PARALLEL_LEVEL_UNSPECIFIED' | 'MIN' | 'OPTIMAL' | 'MAX' — Optional. Parallel level for initial data sync. Currently only applicable for MySQL.

## Response `200`

Successful response

---

[API](https://skmtc.dev/google/apis/sqladmin.md) · [All operations](https://skmtc.dev/google/apis/sqladmin/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/google/sqladmin/revisions/e9eef8a2afcd/schema)