Object Storage Service:ossfs 2.0 release history

Debian 11 and later versions

Reduced metadata memory usage by 10%–20% in typical scenarios, depending on directory structure and file name length.

Improved the data caching model. For open file handles, the latest object data from OSS is now readable even after the attr_timeout expires.

Enhanced fstab-based automatic mount at startup to work on operating systems that lack the mount.fuse component.

Additional stability enhancements and fixes.

Automatic mount at startup via fstab: Configure ossfs 2.0 as a FUSE-based entry in /etc/fstab to mount OSS buckets automatically when the system starts.

`--memory_data_cache_size`: Enables memory cache mode. When multiple processes read the same file concurrently, data is served from memory rather than issuing repeated OSS requests, which reduces bandwidth amplification. This is particularly useful when loading large models across multiple GPUs simultaneously.

`--max_inode_cache_count`: Sets the maximum number of global metadata cache entries.

`--credential_process`: Retrieves access credentials from an external process.

--upload_buffer_size, --prefetch_chunk_size, --total_mem_limit, and --memory_data_cache_size now accept human-readable string values such as 8m, 8MiB, 16g, and 16GiB, in addition to numeric byte values.

Reduced extra ListObjects requests triggered by unexpected readdir interruptions under high system load.

Fixed other stability issues.

Alibaba Cloud Linux 3 on ARM (aarch64)

Fixed a potential crash when system memory is critically low.

Fixed excessive memory usage when many files are open simultaneously.

ETag-based change detection: ossfs 2.0 now uses ETag to determine whether an object's content has changed, providing more reliable detection.

Added ossfs2 mount --help to list all available mount options and their descriptions.

Reduced memory overhead when running ls on large directories.

Enhanced the prefetch_chunks mount option: set to -1 to disable the prefetch memory limit entirely.

Fixed other stability issues.

Ubuntu 20.04, Ubuntu 22.04, and Ubuntu 24.04

`--ram_role`: Uses an ECS RAM role as the OSS access credential, so you do not need to store an AccessKey ID and AccessKey Secret on the instance.

`--oss_negative_cache_timeout` and `--oss_negative_cache_size`: Cache OSS requests that returned a 404 Not Found error. Subsequent requests for the same missing object are served from the cache, reducing duplicate requests to OSS.

Fixed other stability issues.

CentOS 7 and CentOS 8

AccessKey credentials via environment variables: Configure AccessKey ID and AccessKey Secret credentials using environment variables instead of writing credentials to a file.

`uid`, `gid`, `file_mode`, and `dir_mode` mount options: Apply consistent ownership and permission settings to all mounted files and directories.

Automatic Multipurpose Internet Mail Extensions (MIME) type detection: ossfs 2.0 sets the MIME type of OSS objects based on the file name extension when writing files, so objects are stored with the correct content type.

Improved log output: when an OSS request fails, the log now includes the RequestID and EC error code to help with troubleshooting.

Added a default --total_mem_limit on machines with 16 GB or less of system memory to prevent excessive memory consumption.

Fixed other stability issues.