Symptom
After mounting an Object Storage Service (OSS) bucket to Linux with ossfs, file copy operations fail with the following error:
Input/output errorThis error typically occurs when copying large files, which generates a high volume of disk I/O operations.
Cause
Copying a large file significantly increases the disk read and write workload, which can cause a system disk error and trigger this message.
Solution
Increase the multipart upload parameters
Run ossfs -h to view the current default values for multipart upload parameters, then increase them to handle larger files:
| Parameter | Description | Default |
|---|---|---|
parallel_count | Number of concurrent threads for multipart upload of large objects | 5 |
multipart_size | Size of each part in multipart upload, in MB | 10 |
The multipart_size value determines the maximum object size you can upload. A single multipart upload supports up to 10,000 parts. With the default multipart_size of 10 MB, the maximum object size is 100 GB. Increase multipart_size to upload larger objects.
Use ossutil for large file transfers
ossfs is not designed for large file transfers or high-concurrency workloads. For these scenarios, use ossutil instead, which supports resumable multipart upload and download.
Common ossutil use cases:
Download objects from OSS to an Elastic Compute Service (ECS) instance
Upload files from a local or ECS environment to OSS
For more information about ossfs limitations, see ossfs overview.
Applies to
OSS