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README of Chinese


The OSSFS enables you to mount Alibaba Cloud OSS buckets to a local file in Linux/Mac OS X systems. In the system, you can conveniently operate on objects in OSS while using the local file system to maintain data sharing.


The OSSFS is built based on S3FS and has all the features of S3FS. Main features:

  • Support a majority of the POSIX file system features, including file read/write, directory, link operation, permission, uid/gid, and extended attributes).
  • Support upload of large files through the OSS multipart feature.
  • Support MD5 verification to ensure data integrity.

Install OSSFS

Precompiled installer

We have prepared an installer package for common Linux releases:

  • Ubuntu-14.04
  • CentOS-7.0/6.5/5.11

Please select the corresponding installer on the Version Releases Page to download and install the tool. The latest version is recommended.

  • For Ubuntu systems, the installation command is:
sudo apt-get update
sudo apt-get install gdebi-core
sudo gdebi your_ossfs_package
  • For CentOS6.5 or above, the installation command is:
sudo yum localinstall your_ossfs_package
  • For CentOS5, the installation command is:
sudo yum localinstall your_ossfs_package --nogpgcheck

Install by source code

If you fail to find the corresponding installer package, you can also install the tool by compiling the code on your own. First install the following dependency libraries before compilation:

Ubuntu 14.04:

sudo apt-get install automake autotools-dev g++ git libcurl4-gnutls-dev \
                     libfuse-dev libssl-dev libxml2-dev make pkg-config

CentOS 7.0:

sudo yum install automake gcc-c++ git libcurl-devel libxml2-devel \
                 fuse-devel make openssl-devel

Then you can download the source code from GitHub and compile the code for installing the tool:

git clone
cd ossfs
sudo make install


Set the bucket name, access key/ID information and save the information to the "/etc/passwd-ossfs" object. Note: The ACL of this object must be set correctly, and 640 is recommended. 600 is recommended if the password file is not the default path.

echo my-bucket:my-access-key-id:my-access-key-secret > /etc/passwd-ossfs
chmod 640 /etc/passwd-ossfs

Mount the OSS bucket to the specified directory.

ossfs my-bucket my-mount-point -ourl=my-oss-endpoint


Mount the 'my-bucket' bucket to the '/tmp/ossfs' directory and the AccessKeyId is 'faint', the AccessKeySecret is '123', and the OSS endpoint is ''.

echo my-bucket:faint:123 > /etc/passwd-ossfs
chmod 640 /etc/passwd-ossfs
mkdir /tmp/ossfs
ossfs my-bucket /tmp/ossfs -ourl=

Unmount the bucket:

umount /tmp/ossfs # root user
fusermount -u /tmp/ossfs # non-root user

Common settings

  • You can use 'ossfs --version' to view the current version and 'ossfs -h' to view available parameters.

  • If you are using OSSFS on an Alibaba Cloud ECS instance, you can use the intranet domain name to save traffic charges and improve speed:

      ossfs my-bucket /tmp/ossfs -ourl=
  • In a Linux system, updatedb will scan the file system on a regular basis. If you do not want the OSSFS-mounted directory to be scanned, refer to FAQ to configure skipping the mounted directory.

  • If eCryptFs or other systems that require XATTR are not used, you can improve performance by adding the '-o noxattr' parameter.

  • The OSSFS allows you to specify multiple sets of bucket/access_key_id/access_key_secret information. When multiple sets of information are in place, the format of the information written to passwd-ossfs is:

  • The Supervisor is recommended in a production environment to start and monitor the OSSFS process. For usage see FAQ.

Advanced settings

  • You can add the '-f -d' parameters to run the OSSFS in the foreground and output the debug log.
  • You can use the '-o kernel_cache' parameter to enable the OSSFS to use the page cache of the file system. If you have multiple servers mounted to the same bucket and require strong consistency, do not use this option.


Do not panic in case of errors. Troubleshoot the problem following the steps below:

  1. If a printing error occurs, read and understand the error message.

  2. View '/var/log/syslog' or '/var/log/messages' to check for any related information.

     grep 's3fs' /var/log/syslog
     grep 'ossfs' /var/log/syslog
  3. Retry OSSFS mounting and open the debug log:

     ossfs ... -o dbglevel=debug -f -d > /tmp/fs.log 2>&1

    Repeat the operation and save the '/tmp/fs.log' to check or send the file to me.


Compared with local file systems, OSSFS has some restrictions in provided functionality and performance. Specifically speaking:

  • Random or append writes to files may lead to rewrite of the entire file.
  • Metadata operations, such as list directory perform poorly because of the remote access to the OSS server.
  • The rename operations on files/folders are not atomic.
  • When multiple clients are mounted to the same OSS bucket, you have to coordinate actions of various clients on your own. For example, keep multiple clients from writing data to the same file.
  • Hard link is not supported.
  • The tool is not suitable for scenarios with highly concurrent reads/writes as it will increase the system load.

Get involved in development

  1. For the development procedure, refer to:
  2. After the code is submitted, ensure the travis CI is in the PASS status.
  3. Every time a new version is released:
  • Run 'scripts/' to generate the corresponding installer package.
  • Release a version on the Release Page.
  • Upload the generated installer package to the corresponding Release directory.




  • OSSFS Wiki
  • S3FS- Mount the s3 bucket to the local file system through the fuse interface.

Contact us


Copyright (C) 2010 Randy Rizun

Copyright (C) 2015 Haoran Yang

Licensed under the GNU GPL version 2

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