This topic describes how to migrate data by using Data Transport.

Usage notes

When you perform an online migration, take note of the following items:

  • Data Online Migration uses the standard and publicly available API operations provided by the storage service provider of the source data address to access the source data. The data accessed by Data Online Migration depends on the specific API operations that are implemented by the service provider.
  • A migration job occupies the network resources of the source and destination data addresses. To ensure business continuity, we recommend that you specify a rate limit for your migration job or run your migration job during off-peak hours.
  • Before a migration job starts, the system checks the files at the source data address and the destination data address. If the source and destination data addresses have files with the same name, and the last modification time of the source file is later than the last modification time of the destination file, the destination file is overwritten. If both files contain different information, we recommend that you change the name of one file or back up the destination file.
  • Data Online Migration can migrate only data from all versions of a bucket per job. You cannot migrate all data in your account at a time. If you want to migrate data of a specific version, you can specify the data by the file name and version number.
Warning Make sure that you verify the migrated data at the destination data address after the migration task is complete to ensure that the migrated data is correct. If you delete the data at the source data address before you verify the migrated data at the destination data address, you are liable for the losses and consequences caused by any data loss.

Step 1: Create a source data address

  1. Log on to the Alibaba Cloud Data Transport console.
  2. In the left-side navigation pane, choose Data Online Migration > Data Address. On the page that appears, click Create Data Address.
  3. In the Create Data Address panel, configure the following parameters and click OK.
    ParameterRequiredDescription
    Data TypeYesSelect AWS S3.
    Data NameYesEnter a name. The name must be 3 to 63 characters in length. Special characters are not supported, except for hyphens (-) and underscores (_).
    EndpointYesEnter the endpoint of the region where the AWS Simple Storage Service (AWS S3) bucket resides. For more information, see Regions and endpoints.
    BucketYesThe name of the AWS S3 bucket.

    The bucket name cannot contain invalid characters, such as spaces, line breaks, and tab characters.

    PrefixYes
    • Migrate All Data: All data in the bucket is migrated.

      When you migrate all data, you do not need to specify a prefix.

    • Migrate Partial Data: Only the files in the directory that is specified by the prefix are migrated. The prefix must end with a forward slash (/). For example, you can specify data/to/oss/ as a prefix.
    Access Key IdYesSpecify the AccessKey pair that is used to migrate data. Delete the key pair after the migration is complete.
    Secret Access KeyYes
    Use VPCYesIf a virtual private cloud (VPC) is used, the migration job occupies a private IP address in the VPC.

Step 2: Create a destination data address

  1. In the left-side navigation pane, choose Data Online Migration > Data Address. On the page that appears, click Create Data Address.
  2. In the Create Data Address panel, configure the following parameters and click OK.
    ParameterRequiredDescription
    Data TypeYesSelect OSS.
    Data NameYesEnter a name. The name must be 3 to 63 characters in length. Special characters are not supported, except for hyphens (-) and underscores (_).
    Data RegionYesSelect the region where the destination data address is located.
    Enable Transfer AccelerationNoFor Data Online Migration to use the transfer acceleration feature provided by Object Storage Service (OSS), you must enable the transfer acceleration feature for buckets. The transfer acceleration feature takes effect within 30 minutes after it is enabled. After you enable the feature, wait for 30 minutes before you create a migration job.
    Important If you use the transfer acceleration feature to access your OSS buckets, you are charged additional fees for transfer acceleration. For more information, see Enable transfer acceleration.
    OSS EndpointYes
    Select an endpoint in the region where your data is stored. For more information, see Regions and endpoints.
    • http://oss-cn-endpoint.aliyuncs.com: indicates that you use an HTTP-based endpoint to access OSS over the Internet.
    • https://oss-cn-endpoint.aliyuncs.com: indicates that you use an HTTPS-based endpoint to access OSS over the Internet.
    Note If you want to migrate data from third-party cloud services to OSS, you must access OSS from a public endpoint over the Internet.
    AccessKey IdYesSpecify the AccessKey pair that is used to migrate data. For more information, see Preparations.
    AccessKey SecretYes
    OSS BucketYesSelect a bucket to store the migrated data.
    OSS PrefixNoAn OSS prefix cannot start with a forward slash (/) but must end with a forward slash (/). For example, you can specify data/to/oss/ as the OSS prefix. Do not specify this parameter if you want to migrate data to the root directory of the specified bucket.
    Important If the name of a source file starts with a forward slash (/), you must specify an OSS prefix when you configure the destination data address. Otherwise, the migration fails. For example, if the name of a file that you want to migrate is /test/test.png, you must specify an OSS prefix, such as oss/. When the migration is complete, the name of the file changes from /test/test.png to oss//test/test.png.

Step 3: Create a migration job

  1. In the left-side navigation pane, choose Data Online Migration > Migration Jobs. On the page that appears, click Create Job.
  2. In the Create Job panel, read the terms of the migration service and select I agree to the above terms and activate the Data Transport service. Then, click Next.
  3. In the Fee Reminder message, click Yes, Go Ahead.
  4. In the Job Config step, configure the following parameters and click Next.
    ParameterRequiredDescription
    Job NameYesEnter a job name. The name must be 3 to 63 characters in length and can contain only lowercase letters, digits, and hyphens (-). It cannot start or end with a hyphen (-).
    Source Data AddressYesSelect the source data address that you created.
    Destination Data AddressYesSelect the destination data address that you created.
    Specified DirectoryNoSpecify the directories whose files and subdirectories are included or excluded during migration.
    • Do not filter: migrates all data from the source data address.
    • Exclude: does not migrate the files or subdirectories in the specified directories.

      For example, you want to migrate all the directories in the root_dir/ directory except root_dir/bad_sub1/ and root_dir/bad_sub2/. In this case, you can select this method and specify bad_sub1/ and bad_sub2/.

    • Contain: migrates only the files and subdirectories in the specified directories.

      For example, you want to migrate only root_dir/good_sub1/ and root_dir/good_sub2/ in the root_dir/ directory. In this case, you can select this method and specify good_sub1/ and good_sub2/.

    Note
    • A directory name cannot start with a forward slash (/) or a backslash (\), and cannot contain double forward slashes (//), double periods (..), or double quotation marks ("). The character string that consists of all the specified directory names cannot exceed 10 KB in length.
    • A directory name must end with a forward slash (/). For example, you can specify docs/ as a directory name.
    • You can specify up to 20 directories that you want to include or exclude.
    Migration TypeYes
    • Full: The system migrates all data from the source data address to the destination data address. You must configure the Start Time Point of File parameter. The system migrates all data whose last modification time is later than the specified time. After all data is migrated, the migration job ends.

      If you change the data at the source data address after the migration job is complete, you can submit another job to migrate all data. In this case, the system migrates only the changed data.

    • Incremental: The system runs a migration job based on the values that you specified for the Migration Interval and Migration Times parameters.
      • You must configure the Start Time Point of File parameter. During the first migration, the system migrates all data whose last modification time is later than the specified time. After the first migration is complete, incremental migration is performed based on the value that you specified for the Migration Interval parameter. For each incremental migration, the system migrates only the data that is created or modified after the previous migration starts and before the current migration starts.
      • If you set the Migration Times parameter to N, full migration is performed once and then incremental migration is performed (N - 1) times.

        For example, the current time is 08:00, March 10, 2019 and you set the Migration Interval parameter to 1, the Migration Times parameter to 5, and the Start Time Point of File parameter to 08:00, March 5, 2019. When the first migration starts, the system migrates all files whose last modification time is between 08:00, March 5, 2019 and 08:00, March 10, 2019. In this example, the first migration requires one hour to complete and the second migration starts at 10:00, March 10, 2019. The duration from 08:00 to 10:00 consists of one hour for the first migration process and one hour for the migration interval. During the second migration, the system migrates the files whose last modification time is between 08:00, March 10, 2019 and 10:00, March 10, 2019. The migration job consists of one full migration and four incremental migrations.

    Important Before full or incremental migration starts, the system compares the files at the source data address with the files at the destination data address. If a source file has the same name as a destination file, the destination file is overwritten when one of the following conditions is met:
    • The Content-Type values of the source file and the destination file are different.
    • The last modification time of the source file is later than that of the destination file.
    • The size of the source file is different from that of the destination file.
    Multi-version MigrationYes
    • Do not use: Use single-version migration. This is the default setting.
    • Use: Use multi-version migration.
      After you enable multi-version migration, the following dialog box appears. You are prompted to enable multi-version migration for the destination data address. Enable multi-version migration
    Start Time Point of FileYes
    • All: All files are migrated.
    • Assign: Only the files that are created or modified after the specified time are migrated. For example, if you set the parameter to 08:00:00, November 01, 2018, only the files that are created or modified after 08:00:00, November 01, 2018 are migrated. Files that are created or modified before the specified time are skipped during the migration.
    Migration IntervalThis parameter is required when Migration Type is set to Incremental.The default value is one hour and the maximum value is 24 hours.
    Migration TimesThis parameter is required when Migration Type is set to Incremental.The default value is 1 and the maximum value is 30.
    File Overwrite MethodYesThe method that is used to process the source file whose name is the same as that of a destination file. Valid values:
    • LastModified: If a source file has the same name as a destination file, the system compares the last modification time that is indicated by the LastModified property of the files.
      • If the last modification time of the source file is later than that of the destination file, the source file is migrated and the destination file is overwritten.
      • If the last modification time of the source file is earlier than that of the destination file, the source file is not migrated and the destination file is retained.
      • If the two files have the same last modification time, the system checks the values of the Size and Content-Type properties of the files.

        If the two files have the same Size and Content-Type values, the source file is not migrated. If the two files have different values of at least one property, the source file is migrated and the destination file is overwritten.

    • Condition: If a source file has the same name as a destination file, the system compares the values of the LastModified, Size, and Content-Type properties of the two files.
      • If all property values of the two files are the same, the source file is not migrated.
      • If the two files have different values of at least one property, the source file is migrated and the destination file is overwritten.
    • All: If a source file has the same name as a destination file, the system performs no comparison and directly overwrites the destination file with the source file.
    • No: If a source file has the same name as a destination file, the system performs no comparison and directly skips the source file during the migration.
  5. On the Performance tab, navigate to the Data Prediction section and configure the Data Size and File Count parameters.
    Note To ensure a successful migration, we recommend that you estimate the amount of data to be migrated as accurately as possible. For more information, see Estimate the amount of data that you want to migrate.
  6. Optional:On the Performance tab, navigate to the Flow Control section, specify the Time Range and Max Flow(MB/s) parameters, and then click Add.
    Note To ensure business continuity, we recommend that you configure the Time Range and Max Flow parameters based on the traffic fluctuations.
  7. Click Create and wait until the migration job is complete.