FUSE-based file system backed by Amazon S3
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s3fs allows Linux and Mac OS X to mount an S3 bucket via FUSE. s3fs preserves the native object format for files, allowing use of other tools like s3cmd.
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  • large subset of POSIX including reading/writing files, directories, symlinks, mode, uid/gid, and extended attributes
  • compatible with Amazon S3, Google Cloud Storage, and other S3-based object stores
  • large files via multi-part upload
  • renames via server-side copy
  • optional server-side encryption
  • data integrity via MD5 hashes
  • in-memory metadata caching
  • local disk data caching
  • user-specified regions, including Amazon GovCloud
  • authenticate via v2 or v4 signatures


Some systems provide pre-built packages:

  • On Debian 9 and Ubuntu 16.04 or newer:

    sudo apt-get install s3fs
  • On SUSE 12 or newer and openSUSE 42.1 or newer:

    sudo zypper in s3fs
  • On Mac OS X, install via Homebrew:

    $ brew cask install osxfuse
    $ brew install s3fs


  • On Linux, ensure you have all the dependencies:

On Ubuntu 14.04:

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

On CentOS 7:

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

Then compile from master via the following commands:

git clone https://github.com/s3fs-fuse/s3fs-fuse.git
cd s3fs-fuse
sudo make install


The default location for the s3fs password file can be created:

  • using a .passwd-s3fs file in the users home directory (i.e. ~/.passwd-s3fs)
  • using the system-wide /etc/passwd-s3fs file

Enter your S3 identity and credential in a file ~/.passwd-s3fs and set owner-only permissions:

echo MYIDENTITY:MYCREDENTIAL >  ~/.passwd-s3fs
chmod 600  ~/.passwd-s3fs

Run s3fs with an existing bucket mybucket and directory /path/to/mountpoint:

s3fs mybucket /path/to/mountpoint -o passwd_file=~/.passwd-s3fs

If you encounter any errors, enable debug output:

s3fs mybucket /path/to/mountpoint -o passwd_file=~/.passwd-s3fs -o dbglevel=info -f -o curldbg

You can also mount on boot by entering the following line to /etc/fstab:

s3fs#mybucket /path/to/mountpoint fuse _netdev,allow_other 0 0


mybucket /path/to/mountpoint fuse.s3fs _netdev,allow_other 0 0

If you use s3fs with a non-Amazon S3 implementation, specify the URL and path-style requests:

s3fs mybucket /path/to/mountpoint -o passwd_file=~/.passwd-s3fs -o url=http://url.to.s3/ -o use_path_request_style


s3fs#mybucket /path/to/mountpoint fuse _netdev,allow_other,use_path_request_style,url=http://url.to.s3/ 0 0

To use IBM IAM Authentication, use the -o ibm_iam_auth option, and specify the Service Instance ID and API Key in your credentials file:

echo SERVICEINSTANCEID:APIKEY > /path/to/passwd

The Service Instance ID is only required when using the -o create_bucket option.

Note: You may also want to create the global credential file first

echo MYIDENTITY:MYCREDENTIAL > /etc/passwd-s3fs
chmod 600 /etc/passwd-s3fs

Note2: You may also need to make sure netfs service is start on boot


Generally S3 cannot offer the same performance or semantics as a local file system. More specifically:

  • random writes or appends to files require rewriting the entire file
  • metadata operations such as listing directories have poor performance due to network latency
  • eventual consistency can temporarily yield stale data(Amazon S3 Data Consistency Model)
  • no atomic renames of files or directories
  • no coordination between multiple clients mounting the same bucket
  • no hard links


  • goofys - similar to s3fs but has better performance and less POSIX compatibility
  • s3backer - mount an S3 bucket as a single file
  • S3Proxy - combine with s3fs to mount EMC Atmos, Microsoft Azure, and OpenStack Swift buckets
  • s3ql - similar to s3fs but uses its own object format
  • YAS3FS - similar to s3fs but uses SNS to allow multiple clients to mount a bucket

Frequently Asked Questions


Copyright (C) 2010 Randy Rizun rrizun@gmail.com

Licensed under the GNU GPL version 2