Help Center/ Migration Center/ FAQs/ Storage Migration/ What Do I Do If a Migration Task Fails?
Updated on 2025-04-30 GMT+08:00
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What Do I Do If a Migration Task Fails?

To rectify the fault if the workflow status is Failed after the migration is complete, use the following methods:

Method 1: Querying the Failure Cause Using LTS

If log collection is enabled for the migration cluster used by the workflow, you can utilize this method to identify the failure cause from the error logs. Additionally, you can provide these logs to Huawei Cloud technical support for analysis, and they will offer handling suggestions.

  1. Search for LTS on the Huawei Cloud console.

  2. Find the log group for the region where the migration cluster is located. Its name is in the format of oms_lts_log_group_<migration-cluster-ID>.

  3. Click the log group, adjust the time range to when the fault occurred, and search for logs.

    To search for error logs of a list node, enter hostName:oms_cluster_ecs_LIST_* AND ERROR in the search box.

    To search for error logs of a migration node, enter hostName:oms_cluster_ecs_MIGRATION_* AND ERROR in the search box.

    You can use the obtain error logs to analyze the failure cause or submit the logs to Huawei Cloud technical support for analysis and rectification suggestions.

Method 2: Viewing the List of Failed Objects

If the OMS task status in the workflow is failed, find the path of the failed object list in the workflow. Generally, the path is in the oms/<oms2.0-task-ID>/fail directory at the target.

You can also see Failed Object List in the File Statistics area on the workflow details page.

The list of failed objects is in JSON format. Each record indicates an object. The content_handle_result field records the failure cause.

Table 1 Error codes in content_handle_result

Error Codes Returned for Failed Objects (content_handle_result)

Description

Solution

READ_ATTRIBUTE_FAIL_4_LIST

Reading attributes during listing failed.

Check whether the file attributes are normal and whether the file contains abnormal characters.

COMPARISON_ATTRIBUTE_NOT_SAME

After the migration, the attributes of the source and target objects were inconsistent. The possible cause was that the source object changed after the listing.

Keep the source object unchanged and use the Never overwriting policy. Retry the workflow.

WRITE_STREAM_FAIL

Writing data to the target stream failed. The possible cause was that the write stream was preempted.
  1. Retry the workflow. If the retry is successful, the fault is caused by stream interruption.
  2. If the retry still fails, check whether you have the write permission for the target storage system.

UNSUPPORTED_FILE_TYPE

The file type was not supported.

Unsupported file types, such as pipe files, cannot be migrated.

WRITE_ATTRIBUTE_FAIL

Writing attributes at the target failed.

Check whether you have the permissions to modify metadata or attributes for the target storage system.

READ_ATTRIBUTE_FAIL

Read metadata or attributes of the source object failed.

Check whether you have the permissions to obtain the metadata of the source object.

SRC_OBJECT_IS_ARCHIVE

The source object was archived.

Archived source object must be manually restored before they can be migrated.

SRC_FILE_NOT_EXISTS

The source object was not found when it was migrated.

No solutions are available. It is impossible to migrate the source objects that were not found.

COMPARISON_LAST_MODIFY_TIME_OF_SRC_IS_LATER_THAN_DST

When the object was verified for consistency after it was migrated to the target, the system found that the source object was last modified more recently than the paired target object. Generally, the cause was that the source object was modified after being migrated.

Keep the source object unchanged and retry the migration workflow.

COMPLETE_COMPARISON_KMS_NOT_SAME

When the object was verified for consistency after it was migrated to the target, the system found that the source object had a different encryption attribute from the paired target object. This was caused by the encryption setting of the migration workflow.

For example, if the source object was encrypted but the encryption option was not enabled for the migration workflow, the source object will not be encrypted after being migrated to the target.
  1. If the target object has your desired encryption attribute, ignore this error.
  2. If the source object was encrypted and you want to retain its encryption attribute, create a migration workflow again and enable KMS encryption for the workflow.

INIT_SLICE_UPLOAD_FAILED

An error was reported during multipart upload initialization.

Retry the failed object. This error is usually caused by network problems.

MIGRATION_SYM_LINK_FAILED

OBS does not support source symbolic links.

No solutions are available for this OBS compatibility issue.

CREATE_LINK_FAILED

Creating the symbolic link file failed.

Check whether this link file is required. If it is, contact Huawei Cloud technical support.

COMBINE_OBJECT_SLICE_FAILED

Combining file parts failed.

Check whether the account that owns the used AK/SK pair has the permissions to list file parts. If it does not, assign the following permissions to it and try the workflow or task again:

obs:bucket:ListBucketMultipartUploads

For details, see How Do I Obtain Required Permissions for the Source and Destination Platform Accounts?

HANDLE_SLICE_ERROR

Fragment processing failed due to network exceptions or insufficient permissions to read streams.

Retry the workflow or task. If the fault persists, contact Huawei Cloud technical support.

SYM_LINK_IS_NOT_SUPPORT_MIG

Symbolic link files in SMB storage systems cannot be migrated.

No solutions are available for this compatibility issue.

UNPROCESSED_ERROR

An unknown exception occurred.

Contact Huawei technical support.

READ_ATTRIBUTE_FAIL_FOR_SRC

The metadata of the source object failed to be read for post-migration consistency verification. This was usually caused by flow control at the source.

Retry the workflow or task. If the fault persists, check the metadata of the source object.

READ_ATTRIBUTE_FAIL_FOR_DST

The metadata of the target object failed to be read for post-migration consistency verification. This was usually caused by flow control at the target.

Retry the workflow or task. If the fault persists, check the metadata of the target object.

FILE_SIZE_OVER_MAX_SIZE

The maximum number of file parts (10,000) exceeded.

The maximum size of each file part is 1 GB. Objects larger than 1 TB cannot be migrated.

FILE_PATH_TOO_LONG

The file path exceeded the 1,024-character limit allowed by OBS.

The maximum length of a file path in OBS is 1,024 characters. If this limit is exceeded, the file fails to be migrated.
Parent Topic: Storage Migration