Object Storage Service:Troubleshoot failures when uploading large objects with simple upload (PutObject)

Objects larger than 5 GB

The PutObject API has a maximum file size limit of 5 GB. Any attempt to upload an object that exceeds this limit is rejected.

Objects smaller than 5 GB that time out

When you upload a large object from an Elastic Compute Service (ECS) instance over the internal network, the maximum transmission unit (MTU) on the server may be too large. An oversized MTU value can cause network transmission issues that lead to timeouts.

Objects larger than 5 GB: Use multipart upload

For objects that exceed the 5 GB limit of PutObject, use multipart upload to split the object into smaller parts.

You can use the ossutil command line tool to perform multipart upload. The ossutil tool automatically splits a large object into multiple parts and uploads them. For more information, see Multipart upload and resumable upload.

Objects smaller than 5 GB: Adjust the MTU value

If uploads of large objects smaller than 5 GB time out, the MTU on the ECS instance may be too large. Perform the following steps to check and adjust the MTU value:

Step 1: Check the current MTU value

Run the following command on the ECS instance:

netstat -i

The default MTU for the internal and public network interface controllers is 1500.

Step 2: Resolve the issue

Use one of the following methods:

• Method 1: Reduce the MTU value on the ECS instance Run the following command to set the MTU to 1470. This example assumes that the ECS instance accesses OSS over the internal network through eth0:

  ip link set dev eth0 mtu 1470

• Method 2: Use multipart upload Use the multipart upload API or ossutil to upload the object. Multipart upload splits the object into smaller parts, which avoids the timeout issue caused by MTU configuration.