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Object Storage Service:Solution to failure to migrate OSS resources by using the data migration tool ossimport

Last Updated:Mar 20, 2026

ossimport is a data migration tool that moves local, third-party, or OSS data from any region to Object Storage Service (OSS). This page covers the most common reasons ossimport migration jobs fail and how to fix them.

Check the migration status

Run the following command to view the status of a migration job:

bash console.sh stat

Check the JobState value in the output:

JobState valueMeaningNext step
failedThe migration job failed.Check the log to identify the error. See Read the logs.
AbortThe program exited unexpectedly.Contact Alibaba Cloud technical support.

Read the logs

Failed migration logs are written to:

master/jobs/[$JobName]/failed_tasks/[$TaskName]/audit.log

where [$JobName] is the job name and [$TaskName] is the task name.

If the failure occurred while downloading source objects from OSS, check logs/ossimport2.log or logs/import.log for more detail.

Common causes of migration failures

Before looking up a specific error code, check whether any of the following conditions apply to your job:

  • A source file was modified during upload. ossimport records a SIZE_NOT_MATCH error in log/audit.log and uploads only the pre-modification version.

  • A source file was deleted during upload, causing the job to fail.

  • A file name violates OSS naming conventions — for example, a name that starts with a forward slash or is empty.

  • A network issue or permission problem prevented ossimport from downloading the source object from OSS.

Resolve errors by error code

Find your error in the table below and follow the steps in the solution column. After fixing the issue, use the retry command to resume the job.

Error codeError messageCauseSolution
AccessDeniedThe bucket you are attempting to access must be addressed using the specified endpointsrcDomain or destDomain is incorrectEnter the correct endpoint for your region. See Regions and endpoints.
SignatureDoesNotMatchThe request signature we calculated does not match the signature you provideddestAccessKey or destSecretKey is incorrectVerify and correct your AccessKey ID and AccessKey Secret.
N/AThe bucket name"xxx/xx" is invaliddestBucket contains a forward slash or a pathSet destBucket to the bucket name only. Do not include forward slashes or path components.
ConnectionTimeoutConnect to xxx.oss-cn-beijing-internal.aliyuncs.com:80 timed outThe migration host is using an internal endpoint but is not an Elastic Compute Service (ECS) instance, or is not an ECS instance in the same region as the OSS bucket. Internal endpoints are only accessible from ECS instances in the same region.Do one of the following: (1) Switch to a public endpoint in the configuration file, delete the migration job, and resubmit it. (2) Run the migration from an ECS instance in the same region as the OSS bucket.
InvalidBucketNameThe specified bucket is not validdestDomain is set to a subdomain that includes the bucket name (for example, mybucket.oss-cn-beijing.aliyuncs.com) instead of the regional endpointSet destDomain to the regional endpoint only. For a bucket in China (Beijing), use oss-cn-beijing.aliyuncs.com. See Sample configuration files.
RequestTimeTooSkewedUnable to execute HTTP request: The Difference between... is too largeThe system clock on the migration host differs from OSS server time by more than 15 minutes, or high CPU utilization from concurrent uploads is causing delaysDo one of the following: (1) Sync the system clock on the migration host with the OSS server time. (2) If high concurrency is the cause, reduce the value of workerTaskThreadNum in sys.properties to lower the number of concurrent uploads.
N/AThe object key"/xxxxx.jpg" is invalidsrcPrefix is set to a directory path that does not end with a forward slash (/), or destPrefix starts with a forward slash (/) or backslash (\)Check srcPrefix: if the value points to a directory, it must end with /. Check destPrefix: remove any leading forward slashes or backslashes.
N/ANo route to hostThe network path from the migration host to the source or destination is blocked, typically by local firewalls or iptables rulesRun ping to test connectivity from the migration host to both the source and destination. If connectivity is normal, check whether local firewall rules or iptables are blocking the connection. You can also try disabling the firewall. If connectivity is abnormal, fix the network issue and retry.
N/AUnknown http list file formatThe HTTP list file used in HTTP mode migration has an incorrect format or line endingsIf the file was copied from another OS, convert the line endings: on Linux, use mac2unix or dos2unix. On Windows, use a format conversion tool. If the content format is wrong, correct it according to the specification in the"Configuration files" section of Architectures and configurations.

Retry after partial failures

If most files migrated successfully but some failed, follow these steps:

  1. Open the failed file list to get the paths of files that did not migrate:

    master/jobs/[$JobName]/failed_tasks/[$TaskName]/error.list
  2. For each failed file, check whether:

    • You have permission to access the file

    • The file has been deleted

    • The file is a symbolic link

    • The file name contains garbled characters

  3. Fix any issues found, then run the retry command to migrate the failed files again.

Applicable scope

  • Object Storage Service (OSS)

  • ossimport