您可以使用備份和還原流程，透過資料庫遷移服務將 SQL Server 資料庫遷移至 Cloud SQL for SQL Server 執行個體。您必須先將完整資料庫備份和交易記錄檔案上傳至 Cloud Storage 值區。資料庫遷移服務會主動監控您的儲存格，並持續將資料複製到 SQL Server 適用的 Cloud SQL 目的地執行個體。
只要遵循版本相容性指南，您就可以使用資料庫移轉服務，在相同的 SQL Server 版本和版本之間遷移，或是從舊版 SQL Server 遷移至 Cloud SQL 支援的新版。如需更多資訊，請參閱 Microsoft 說明文件，瞭解 SQL Server 版本支援的版本和版本升級。例如，請參閱「
支援的版本和版本升級 (SQL Server 2022)」一文。
下表列出所有支援的 SQL Server 來源和目標資料庫：
來源資料庫
目的地資料庫
Amazon RDS
SQL Server 適用的 Cloud SQL 2022、2019 和 2017 版
自行代管的 SQL Server
(位於地端部署系統或任何雲端 VM 上，且由您完全控管)
持續遷移資料流
對於從相同系統的 SQL Server 遷移至 Cloud SQL，資料庫移轉服務支援
持續遷移流程。在這種方法中，系統會先從完整資料庫備份檔案載入資料，然後再從差異備份檔案載入資料，最後根據您上傳至專屬 Cloud Storage 值區的交易記錄檔案持續更新資料。
圖 1. 資料庫移轉服務在 SQL Server 遷移作業期間移動資料。(按一下即可放大)
大致來說，資料會經過以下遷移階段：
將備份檔案上傳至 Cloud Storage。
持續的 SQL Server 遷移作業需要先備份來源資料庫，然後將備份檔案上傳至 Cloud Storage 值區。針對後續更新，您可以選擇提供差異備份檔案，然後上傳交易記錄檔案。您也可以自動建立及上傳持續交易記錄。
[[["容易理解","easyToUnderstand","thumb-up"],["確實解決了我的問題","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["難以理解","hardToUnderstand","thumb-down"],["資訊或程式碼範例有誤","incorrectInformationOrSampleCode","thumb-down"],["缺少我需要的資訊/範例","missingTheInformationSamplesINeed","thumb-down"],["翻譯問題","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],["上次更新時間：2025-09-08 (世界標準時間)。"],[[["\u003cp\u003eDatabase Migration Service allows the migration of SQL Server databases to Cloud SQL for SQL Server using a backup and restore method, where full database backups and transaction logs are uploaded to Cloud Storage.\u003c/p\u003e\n"],["\u003cp\u003eThe service supports various source databases, including Amazon RDS and self-managed SQL Servers, and can migrate between different SQL Server versions as long as version compatibility guidelines are met.\u003c/p\u003e\n"],["\u003cp\u003eData migration occurs in a continuous flow, starting with a full backup, followed by an optional differential backup, and then ongoing updates from transaction log files uploaded to a designated Cloud Storage bucket.\u003c/p\u003e\n"],["\u003cp\u003eDatabase Migration Service offers monitoring capabilities, including real-time diagnostics and detailed logs, to track the progress and health of the migration process.\u003c/p\u003e\n"],["\u003cp\u003eThe migration service can handle encrypted SQL Server backups, ensuring data security by decrypting the files using an uploaded encryption key during the migration process.\u003c/p\u003e\n"]]],[],null,["# Database Migration Service for SQL Server\n\nYou can migrate SQL Server databases to Cloud SQL for SQL Server\ninstances with Database Migration Service by using a backup and restore flow.\nYou first upload the full database backup and transaction\nlog files to a Cloud Storage bucket. Database Migration Service then actively\nmonitors your bucket, and continuously replicates your data to the destination\nCloud SQL for SQL Server instance.\n\nThis page provides an overview of the key Database Migration Service\nfeatures for homogeneous SQL Server migrations:\n\n- [Supported source and destination](#supported-src-and-dest) lists all SQL Server\n versions supported by Database Migration Service.\n\n- [Continuous migrations data flow](#data-flow-migration-types) provides an end-to-end overview\n of how your data moves in Google Cloud during the migration process.\n\n- [Monitoring](#monitoring)\n gives an introduction for logs and metrics that can\n help you observe the progress and health of your migration job.\n\n- [Encryption](#securing-migration-jobs) looks at how you can migrate\n with encrypted SQL Server backup files.\n\nSupported source and destination databases\n------------------------------------------\n\nYou can use Database Migration Service to migrate between the same SQL Server\nversion and edition, or from earlier versions of\nSQL Server to later versions supported in Cloud SQL, as long\nas you follow the version compatibility guidelines. For more information,\nsee the supported version and edition upgrades for your SQL Server\nversion in Microsoft documentation. For example, see\n[Supported version and edition upgrades (SQL Server 2022)](https://learn.microsoft.com/en-us/sql/database-engine/install-windows/supported-version-and-edition-upgrades-2022?view=sql-server-ver16#upgrades-from-earlier-versions-to-sql-server-2022).\n\nThe following table lists all supported SQL Server source and destination\ndatabases:\n\nContinuous migrations data flow\n-------------------------------\n\nFor homogeneous SQL Server migrations to Cloud SQL,\nDatabase Migration Service supports the\n[continuous migration](/database-migration/docs/overview#migrationconcepts) flow. In this approach, your data is first\nloaded from a full database backup file, then from a differential backup file,\nand then continuously updated based on transaction log files you upload to\na dedicated Cloud Storage bucket.\n[](#lightbox-trigger) **Figure 1.** Data movement during Database Migration Service for SQL Server migrations. (click to enlarge)\n\nAt a high level, your data moves through the migration phases as follows:\n\n1. You upload your backup files to Cloud Storage.\n\n Continuous SQL Server migrations require that you first take a\n full backup of your source database, and then upload the backup file to\n a Cloud Storage bucket.\n For subsequent updates, you can optionally provide a differential backup file,\n and then upload transaction log files.\n You can also automate continuous transaction log creation and uploads.\n - For more information on automating continuous transaction log creation and\n uploads, see\n [Schedule transaction log backups](/database-migration/docs/sqlserver/automate-backup-exports).\n\n - For details on how Database Migration Service uses different types of backup files\n in homogeneous SQL Server migrations, see\n [Supported backup file types](/database-migration/docs/sqlserver/supported-backup-files).\n\n2. When the migration job starts, Database Migration Service loads the latest full\n database backup to the destination Cloud SQL for SQL Server instance.\n\n3. Once the initial load is complete, Database Migration Service switches to the incremental\n load phase. At this point, Database Migration Service performs the following:\n\n 1. If your migration job is configured to use a differential backup file,\n Database Migration Service scans the `diff` folder and loads differential backup\n files to your destination instance. If your migration job is configured\n to use a differential backup file, but Database Migration Service can't find it\n in the Cloud Storage bucket, the migration job shows an error\n while continuously searching the `diff` folder for the differential\n backup file.\n\n Database Migration Service loads differential backup files only once, at the beginning\n of the incremental load phase. When the migration job proceeds to work with\n transaction log files no new differential backup files are recognized when\n you upload them to the `diff` folder.\n 2. Now Database Migration Service continuously scans your Cloud Storage bucket\n for transaction log backup files to replicate on your destination instance.\n\n4. As new data shows up in your source database, you can keep exporting\n the transaction log backup files and uploading them to the same Cloud Storage\n bucket. Database Migration Service picks up all new transaction log backup files and\n replicates them on the destination database.\n\nYou can stop the ongoing replication and promote the migration job when you want\nto switch your application to so that it uses the Cloud SQL for SQL Server\ndestination instance as the production database. For a detailed step-by-step\nmigration guide, see\n[Cloud SQL for SQL Server migration guide](/database-migration/docs/sqlserver/guide).\n\nMonitoring\n----------\n\n[](#lightbox-trigger) **Figure 2.** Sample observability diagram in Database Migration Service. (click to enlarge)\n\nDatabase Migration Service provides extensive logging and observability capabilities\nto help you monitor the migration progress. These features include real-time\ndiagnostics for replication delay and transaction log backup file processing,\nas well as detailed logs for Cloud SQL for SQL Server destination instance health\nand migration job state.\n\nFor more details, see\n[Migration job metrics](/database-migration/docs/sqlserver/migration-job-metrics).\n\nEncryption\n----------\n\nDatabase Migration Service is fully compatible with\n[encrypted SQL Server backups](https://learn.microsoft.com/en-us/sql/relational-databases/backup-restore/backup-encryption). If you upload your\nencryption key to Google Cloud, Database Migration Service can safely decrypt\nyour data and load it to the Cloud SQL for SQL Server destination instance without\ncompromising your data security.\n\nFor more details, see\n[Encrypted SQL Server backup files](/database-migration/docs/sqlserver/backup-file-encryption).\n\nWhat's next\n-----------\n\n- To learn more about SQL Server data and feature support in\n Database Migration Service, see\n [Known limitations](/database-migration/docs/sqlserver/known-limitations).\n\n- To get a complete, step-by-step migration walkthrough, see\n [Cloud SQL for SQL Server migration guide](/database-migration/docs/sqlserver/guide)."]]
