Data Online Migration:Migrate data

Usage notes

When you migrate data by using Data Online Migration, take note of the following items:

• Data Online Migration accesses the source data address by using the public interfaces provided by the storage service provider of the source data address. The access behavior depends on the interface implementation of the storage service provider.

• When Data Online Migration is used for migration, it consumes resources at the source and destination data addresses. This may interrupt your business. To ensure business continuity, we recommend that you enable throttling for your migration tasks or run the migration tasks during off-peak hours after careful assessment.

• Before a migration task starts, Data Online Migration checks the files at the source and destination data addresses. If a file at the source data address and a file at the destination data address have the same name, and the File Overwrite Method parameter of the migration task is set to Yes, the file at the destination data address is overwritten during migration. If the two files contain different information and the file at the destination data address needs to be retained, we recommend that you change the name of one file or back up the file at the destination data address.

• The LastModifyTime attribute of the source file is retained after the file is migrated to the destination bucket. If a lifecycle rule is configured for the destination bucket and takes effect, the migrated file whose last modification time is within the specified time period of the lifecycle rule may be deleted or archived in specific storage types.

Limits

• If the static website hosting feature is enabled for the files at the source data address, directories that do not exist are found during the scanning for data migration. For example, if you upload the myapp/resource/1.jpg file and enable the static website hosting feature for the file, the following objects are found during the scanning for data migration: myapp/, myapp/resource/, and myapp/resource/1.jpg. The myapp/ and myapp/resource/ directories fail to be migrated because they do not exist. The myapp/resource/1.jpg file is migrated as expected.

• Symbolic links that exist at the source data address are directly migrated to the destination data address. For more information, see Create symbolic links.

• Data Online Migration allows you to migrate only the data of a single bucket in a task. You cannot migrate all data that belongs to your account in a single task.

• Data Online Migration does not support data migration in Alibaba Finance Cloud or Alibaba Gov Cloud.

• Only specific attributes of data can be migrated between OSS buckets.

  • Attributes that can be migrated are x-oss-meta-*, LastModifyTime, Content-Type, Cache-Control, Content-Encoding, Content-Disposition, Content-Language, and Expires.

  • Attributes that cannot be migrated include but are not limited to StorageClass, Acl, server-side encryption, Tagging, and user-defined x-oss-persistent-headers.

    Note

    The attributes that cannot be migrated include but are not limited to the preceding attributes. Check the actual migration results to find out other attributes that cannot be migrated.

Step 1: Select a region

Procedure

1. Log on to the Data Online Migration console as the Resource Access Management (RAM) user that you created for data migration.

   Note

   To migrate data across Alibaba Cloud accounts, you can log on as a RAM user that is created within the source or destination Alibaba Cloud account.

2. In the upper-left corner of the top navigation bar, select the region in which the source data address resides or select the region that is closest to the region in which the source data address resides.

   The region that you select is the region in which your Data Online Migration is deployed. Supported regions inside China include China (Beijing), China (Shanghai), China (Hangzhou), China (Shenzhen), China (Ulanqab), and China (Hong Kong), and supported regions outside China include Singapore, Germany (Frankfurt), and US (Virginia).

   Important

   • The data addresses and migration tasks that you create in a region cannot be used in another region. Select the region with caution.

   • We recommend that you select the region in which the source data address resides. If the region in which the source data address resides is not supported by Data Online Migration, select the region that is closest to the region in which the source data address resides.

   • To speed up cross-border data migration, we recommend that you enable transfer acceleration. If you enable transfer acceleration for OSS buckets, you are charged transfer acceleration fees. For more information, see Transfer acceleration.

Step 2: Create a source data address

1. In the left-side navigation pane, choose Data Online Migration > Address Management. On the Address Management page, click Create Address.

2. In the Create Address panel, configure the parameters and click OK. The following table describes the parameters.

   Parameter	Required	Description
   Name	Yes	The name of the source data address. The name must meet the following requirements: The name is 3 to 63 characters in length. The name must be case-sensitive and can contain lowercase letters, digits, hyphens (-), and underscores (_). The name is encoded in the UTF-8 format and cannot start with a hyphen (-) or an underscore (_).
   Type	Yes	The type of the source data address. Select Alibaba OSS.
   Custom Domain Name	No	Specifies whether custom domain names are supported.
   Region	Yes	The region in which the source data address resides. Example: China (Hangzhou).
   Authorize Role	Yes	The source bucket belongs to the Alibaba Cloud account that is used to log on to the Data Online Migration console We recommend that you create and authorize a RAM role in the Data Online Migration console. For more information, see Authorize a RAM role in the Data Online Migration console. You can also manually attach policies to a RAM role in the RAM console. For more information, see the "Step 3: Grant permissions on the source bucket to a RAM role" section of the Preparations topic. The source bucket does not belong to the Alibaba Cloud account that is used to log on to the Data Online Migration console You can attach policies to a RAM role in the OSS console. For more information, see the "Step 3: Grant permissions on the source bucket to a RAM role" section of the Preparations topic.
   Bucket	Yes	The name of the OSS bucket in which the data to be migrated is stored.
   Prefix	No	The prefix of the source data address. You can specify a prefix to migrate specific data. The prefix cannot start with a forward slash (/) but must end with a forward slash (/). Example: data/to/oss/. Specify a prefix for the source data address: For example, you set the prefix of the source data address to example/src/, store a file named example.jpg in example/src/, and set the prefix of the destination data address to example/dest/. After the example.jpg file is migrated to the destination data address, the full path of the file is example/dest/example.jpg. Do not specify a prefix for the source data address: For example, you specify no prefix for the source data address, the path of the file to be migrated is srcbucket/example.jpg, and you set the prefix of the destination data address to destbucket/. After the example.jpg file is migrated to the destination data address, the full path of the file is destbucket/srcbucket/example.jpg.
   Tunnel	No	The name of the tunnel that you want to use. Important This parameter is required only when you migrate data to the cloud by using Express Connect circuits or VPN gateways or migrate data from self-managed databases to the cloud. If data at the destination data address is stored in a local file system or you need to migrate data over an Express Connect circuit in an environment such as Alibaba Finance Cloud or Apsara Stack, you must create and deploy an agent.
   Agent	No	The name of the agent that you want to use. Important This parameter is required only when you migrate data to the cloud by using Express Connect circuits or VPN gateways or migrate data from self-managed databases to the cloud. You can select up to 30 agents at a time for a specific tunnel.

Step 3: Create a destination data address

1. In the left-side navigation pane, choose Data Online Migration > Address Management. On the Address Management page, click Create Address.

2. In the Create Address panel, configure the parameters and click OK. The following table describes the parameters.

Parameter	Required	Description
Name	Yes	The name of the destination data address. The name must meet the following requirements: The name is 3 to 63 characters in length. The name must be case-sensitive and can contain lowercase letters, digits, hyphens (-), and underscores (_). The name is encoded in the UTF-8 format and cannot start with a hyphen (-) or an underscore (_).
Type	Yes	The type of the destination data address. Select Alibaba OSS.
Custom Domain Name	No	Specifies whether custom domain names are supported.
Region	Yes	The region in which the destination data address resides. Example: China (Hangzhou).
Authorize Role	Yes	The destination bucket belongs to the Alibaba Cloud account that is used to log on to the Data Online Migration console We recommend that you create and authorize a RAM role in the Data Online Migration console. For more information, see Authorize a RAM role in the Data Online Migration console. You can also manually attach policies to a RAM role in the RAM console. For more information, see the "Step 4: Grant permissions on the destination bucket to the RAM role" section of the Preparations topic. The destination bucket does not belong to the Alibaba Cloud account that is used to log on to the Data Online Migration console You can attach policies to a RAM role in the OSS console. For more information, see the "Step 4: Grant permissions on the destination bucket to the RAM role" section of the Preparations topic.
Bucket	Yes	The name of the OSS bucket to which the data is migrated.
Prefix	No	The prefix of the destination data address. You can specify a prefix to migrate specific data. The prefix cannot start with a forward slash (/) but must end with a forward slash (/). Example: data/to/oss/. Specify a prefix for the destination data address: For example, you set the prefix of the source data address to example/src/, store a file named example.jpg in example/src/, and set the prefix of the destination data address to example/dest/. After the example.jpg file is migrated to the destination data address, the full path of the file is example/dest/example.jpg. Do not specify a prefix for the destination data address: If you do not specify a prefix for the destination data address, the source data is migrated to the root directory of the destination bucket.
Tunnel	No	The name of the tunnel that you want to use. Important This parameter is required only when you migrate data to the cloud by using Express Connect circuits or VPN gateways or migrate data from self-managed databases to the cloud. If data at the destination data address is stored in a local file system or you need to migrate data over an Express Connect circuit in an environment such as Alibaba Finance Cloud or Apsara Stack, you must create and deploy an agent.
Agent	No	The name of the agent that you want to use. Important This parameter is required only when you migrate data to the cloud by using Express Connect circuits or VPN gateways or migrate data from self-managed databases to the cloud. You can select up to 30 agents at a time for a specific tunnel.

Step 4: Create a migration task

1. In the left-side navigation pane, choose Data Online Migration > Migration Tasks. On the Migration Tasks page, click Create Task.

2. In the Select Address step, configure the parameters and click Next. The following table describes the parameters.

   Parameter	Required	Description
   Name	Yes	The name of the migration task. The name must meet the following requirements: The name is 3 to 63 characters in length. The name must be case-sensitive and can contain lowercase letters, digits, hyphens (-), and underscores (_). The name is encoded in the UTF-8 format and cannot start with a hyphen (-) or an underscore (_).
   Source Address	Yes	The source data address that you created.
   Destination Address	Yes	The destination data address that you created.

3. In the Task Configurations step, configure the parameters that are described in the following table.

   Parameter	Required	Description
   Migration Bandwidth	No	The maximum bandwidth that is available to the migration task. Valid values: Default: Use the default upper limit for the migration bandwidth. The actual migration bandwidth depends on the file size and the number of files. Specify an upper limit: Specify a custom upper limit for the migration bandwidth as prompted. Important The actual migration speed depends on multiple factors, such as the source data address, network, throttling at the destination data address, and file size. Therefore, the actual migration speed may not reach the specified upper limit. Specify a reasonable value for the upper limit of the migration bandwidth based on the evaluation of the source data address, migration purpose, business situation, and network bandwidth. Inappropriate throttling may affect business performance.
   Files Migrated Per Second	No	The maximum number of files that can be migrated per second. Valid values: Default: Use the default upper limit for the number of files that can be migrated per second. Specify an upper limit: Specify a custom upper limit as prompted for the number of files that can be migrated per second. Important The actual migration speed depends on multiple factors, such as the source data address, network, throttling at the destination data address, and file size. Therefore, the actual migration speed may not reach the specified upper limit. Specify a reasonable value for the upper limit of the migration bandwidth based on the evaluation of the source data address, migration purpose, business situation, and network bandwidth. Inappropriate throttling may affect business performance.
   Overwrite Method	Yes	Specifies whether to overwrite a file at the destination data address if the file has the same name as a file at the source data address. Valid values: Do not overwrite: does not migrate the file at the source data address. Overwrite All: overwrites the file at the destination data address. Overwrite based on the last modification time: If the last modification time of the file at the source data address is later than that of the file at the destination data address, the file at the destination data address is overwritten. If the last modification time of the file at the source data address is the same as that of the file at the destination data address, the file at the destination data address is overwritten if the files differ from one of the following aspects: size and Content-Type header. Warning If you select Overwrite based on the last modification time, a newer file may be overwritten by an older one that has the same name. If you select Overwrite based on the last modification time, make sure that the file at the source data address contains information such as the last modification time, size, and Content-Type header. Otherwise, the overwrite policy may become invalid and unexpected migration results may occur. If you select Do not overwrite or Overwrite based on the last modification time, the system sends a request to the source and destination data addresses to obtain the meta information and determines whether to overwrite a file. Therefore, request fees are generated for the source and destination data addresses.
   Migration Report	Yes	Specifies whether to push a migration report. Valid values: Do not push (default): does not push the migration report to the destination bucket. Push: pushes the migration report to the destination bucket. For more information, see Subsequent operations. Important The migration report occupies storage space at the destination data address. The migration report may be pushed with a delay. Wait until the migration report is generated. A unique ID is generated for each execution of a task. A migration report is pushed only once. We recommend that you do not delete the migration report unless necessary.
   Migration Logs	Yes	Specifies whether to push migration logs to Simple Log Service (SLS). Valid values: Do not push (default): does not push migration logs. Push: pushes migration logs to SLS. You can view the migration logs in the SLS console. Push only file error logs: pushes only error migration logs to SLS. You can view the error migration logs in the SLS console. If you select Push or Push only file error logs, Data Online Migration creates a project in SLS. The name of the project is in the aliyun-oss-import-log-Alibaba Cloud account ID-Region of the Data Online Migration console format. Example: aliyun-oss-import-log-137918634953****-cn-hangzhou. Important To prevent errors in the migration task, make sure that the following requirements are met before you select Push or Push only file error logs: SLS is activated. You have confirmed the authorization on the Authorize page.
   Authorize	No	This parameter is displayed if you set the Migration Logs parameter to Push or Push only file error logs. Click Authorize to go to the Cloud Resource Access Authorization page. On this page, click Confirm Authorization Policy. The RAM role AliyunOSSImportSlsAuditRole is created and permissions are granted to the RAM role.
   File Name	No	The filter based on the file name. Both inclusion and exclusion rules are supported. However, only the syntax of specific regular expressions is supported. For more information about the syntax of regular expressions, visit re2. Example: .*\.jpg$ indicates all files whose names end with .jpg. By default, ^file.* indicates all files whose names start with file in the root directory. If a prefix is configured for the source data address and the prefix is data/to/oss/, you need to use the ^data/to/oss/file.* filter to match all files whose names start with file in the specified directory. .*/picture/.* indicates files whose paths contain a subdirectory called picture. Important If an inclusion rule is configured, all files that meet the inclusion rule are migrated. If multiple inclusion rules are configured, files are migrated as long as one of the inclusion rules is met. For example, the picture.jpg and picture.png files exist and the inclusion rule .*\.jpg$ is configured. In this case, only the picture.jpg file is migrated. If the inclusion rule .*\.png$ is configured at the same time, both files are migrated. If an exclusion rule is configured, all files that meet the exclusion rule are not migrated. If multiple exclusion rules are configured, files are not migrated as long as one of the exclusion rules is met. For example, the picture.jpg and picture.png files exist and the exclusion rule .*\.jpg$ is configured. In this case, only the picture.png file is migrated. If the exclusion rule .*\.png$ is configured at the same time, neither file is migrated. Exclusion rules take precedence over inclusion rules. If a file meets both an exclusion rule and an inclusion rule, the file is not migrated. For example, the file.txt file exists, and the exclusion rule .*\.txt$ and the inclusion rule file.* are configured. In this case, the file is not migrated.
   File Modification Time	No	The filter based on the last modification time of files. You can specify the last modification time as a filter rule. If you specify a time period, only the files whose last modification time is within the specified time period are migrated. Examples: If you specify January 1, 2019 as the start time and do not specify the end time, only the files whose last modification time is not earlier than January 1, 2019 are migrated. If you specify January 1, 2022 as the end time and do not specify the start time, only the files whose last modification time is not later than January 1, 2022 are migrated. If you specify January 1, 2019 as the start time and January 1, 2022 as the end time, only the files whose last modification time is not earlier than January 1, 2019 and not later than January 1, 2022 are migrated.
   Execution Time	No	Important If the current execution of a migration task is not complete by the next scheduled start time, the task starts its next execution at the subsequent scheduled start time after the current migration is complete. This process continues until the task is run the specified number of times. If Data Online Migration is deployed in the China (Hong Kong) region or the regions in the Chinese mainland, up to 10 concurrent migration tasks are supported. If Data Online Migration is deployed in regions outside China, up to five concurrent migration tasks are supported. If the number of concurrent tasks exceeds the limit, executions of tasks may not be complete as scheduled. The time when the migration task is run. Valid values: Immediately: The task is immediately run. Scheduled Task: The task is run within the specified time period every day. By default, the task is started at the specified start time and stopped at the specified stop time. Periodic Scheduling: The task is run based on the execution frequency and number of execution times that you specify. Execution Frequency: You can specify the execution frequency of the task. Valid values: Every Hour, Every Day, Every Week, Certain Days of the Week, and Custom. For more information, see the Supported execution frequencies section of this topic. Executions: You can specify the maximum number of execution times of the task as prompted. By default, if you do not specify this parameter, the task is run once. Important You can manually start and stop tasks at any point in time. This is not affected by the custom execution time of tasks.

4. Read Data Online Migration Agreement. Select I have read and agree to the Alibaba Cloud International Website Product Terms of Service. and I have understood that when the migration task is complete, the migrated data may be different from the source data. Therefore, I have the obligation and responsibility to confirm the consistency between the migrated data and source data. Alibaba Cloud is not responsible for the confirmation of the consistency between the migrated data and source data. Then, click Next.

5. Verify that the configurations are correct and click OK. The migration task is created.

Supported execution frequencies

Step 5: Verify data