Data Online Migration:Common causes of a migration failure and solutions

Issue description

Cause

BOS sets traffic throttling on the source data address due to a large number of requests.

Solution

Issue description

Cause

The last modification time of files at the source data address is later than the last modification time of files at the destination data address. A file verification error occurs if you update source files after these files have been migrated to the destination bucket.

Solution

Migrate the updated source files.

Issue description

Cause

A connection that is used to send or receive data is closed by OSS. If the interval between two uploads exceeds 1 minute, the connection that is used to upload data is closed by OSS. Generally, the error is caused by network issues such as high network latency.

Solution

Retry the migration job.

Issue description

Cause

The source and destination data addresses have files with the same name. The last modification time of the file at the destination data address is later than the last modification time of the file at the source data address. The file is disregarded during the migration. However, an error may occur when the system checks the file after the migration job is complete.

Solution

• If you need to migrate the file, you can retry the migration after you delete the file at the destination data address or modify the file name.

• If you do not need to migrate the file, you can ignore the error.

Issue description

Cause

Insufficient permissions are granted. When you create data addresses, you must use an account that has the read permissions on the source data address and the write permissions on the destination data address. After a migration job is started, an error occurs if you modify the permissions of the account or the access permissions of OSS buckets, such as modifying the policies for OSS buckets.

Solution

Retry the migration after you restore the permissions of the account.

Issue description

Cause

Data Online Migration does not allow you to migrate archive files. The error occurs when archive files exist at the source data address.

Solution

• If you need to migrate archive files, retry the migration after you change the file type to Standard.

• If you do not need to migrate the files, ignore this error.

Issue description

check usermeta failed

Cause

The HTTP header or user metadata of a file contains special characters that cannot be identified during the migration.

Solution

• Retry the migration after you modify the HTTP header or user metadata of the file.

• Manually migrate the file that fails to be migrated.

Issue description

When you migrate data from File Storage NAS (NAS) to OSS, the migration job status is displayed as Invalid. Move the pointer over the icon. The following error message is displayed: It is timeout to check the data source, please make sure all the parameters are correct and retry later.

Cause

The IP address of the elastic network interface (ENI) used for migration cannot access the NAS file system in the virtual private cloud (VPC).

Solution

Check whether access control or security groups are configured for the NAS file system. IP addresses used for migration are dynamic and random. You must authorize all IP addresses in the VPC to access the NAS file system.

Issue description

Requests specifying Server Side Encryption with AWS KMS managed keys must be made over a secure connection.

Cause

The error message indicates that the current connection is not secure.

Solution

We recommend that you use an endpoint with HTTPS connections.

Issue description

When you migrate data between OSS buckets, the UserDisable error message is displayed for the files that fail to be migrated.

Cause

Your account is disabled due to multiple possible reasons. For example, OSS is not activated for your account, or your account has overdue payments or security risks. In these cases, the UserDisable error occurs.

Solution

Check whether the account of the source and destination buckets has activated OSS and whether the account has overdue payments. You can also contact Alibaba Cloud OSS technical support to check whether the account is disabled.

Issue description

When you create a NAS data address, the state of the address is Invalid. Move the pointer over the icon. The following error message is displayed: mgw.service.agent.sAddrPrefixInvalid.

Cause

The prefix in the data address is invalid or no file exists in the data address.

Solution

• Check whether the specified prefix is valid.

• Make sure that at least one file exists in the data address.

Issue description

When you migrate NAS files, the amount of data in the source is 5.8 TB, whereas the amount of data migrated to the destination is 11 TB. The amounts of data in the source and destination greatly differ.

Cause

If symbolic links exist in the source, the files to which the symbolic links point are migrated to the destination. However, the symbolic links are not migrated. This way, the actual amount of migrated data is larger than the estimated amount, and the migration progress is beyond 100%. The actual volume of migrated data prevails.

Solution

Check whether the source contains symbolic links. If yes, we recommend that you pause the migration task, process the symbolic links, and then create a new migration task.

Issue description

When you create a NAS data address, the data address remains in the Creating state for more than half an hour.

Cause

An error occurs when resources are allocated.

Solution

We recommend that you delete the data address and create a data address again.

Issue description

When you create a NAS data address, the status of the address is Abnormal. Move the pointer over the icon. The following error message is displayed: mgw.service.agent.dMountNasFailed.

Cause

Solution

• Check whether access control or security groups are configured for the NAS file system. IP addresses used for migration are dynamic and random. You must authorize all IP addresses in the VPC to access the NAS file system.

• Check whether the prefix in the data address is valid and whether the path of the shared folder is the same as the subdirectory that you specify for the data address.

• Check whether the shared folder on the ECS instance is available and whether the NFS service is enabled.

Issue description

When you migrate data from an OSS bucket in the China (Shenzhen) region to an OSS bucket in the China (Hong Kong) region, the migration task is in the Failed state.

Cause

The network between regions in the Chinese mainland and the China (Hong Kong) region is unstable. An error occurs when the network connection times out.

Solution

Create a migration task again in another time period.