s3fs

s3fs allows Linux and macOS to mount an S3 bucket via FUSE. s3fs preserves the native object format for files, allowing use of other tools like AWS CLI.

Features

• 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
• allows random writes and appends
• 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

Installation

Many systems provide pre-built packages:

• Amazon Linux via EPEL:

  sudo amazon-linux-extras install epel
  sudo yum install s3fs-fuse
  

• Debian 9 and Ubuntu 16.04 or newer:

  sudo apt install s3fs
  

• Fedora 27 or newer:

  sudo dnf install s3fs-fuse
  

• Gentoo:

  sudo emerge net-fs/s3fs
  

• RHEL and CentOS 7 or newer through via EPEL:

  sudo yum install epel-release
  sudo yum install s3fs-fuse
  

• SUSE 12 and openSUSE 42.1 or newer:

  sudo zypper install s3fs
  

• macOS via Homebrew:

  brew cask install osxfuse
  brew install s3fs
  

Otherwise consult the compilation instructions.

Examples

s3fs supports the standard AWS credentials file stored in ${HOME}/.aws/credentials. Alternatively, s3fs supports a custom passwd file.

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

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

Enter your credentials in a file ${HOME}/.passwd-s3fs and set owner-only permissions:

echo ACCESS_KEY_ID:SECRET_ACCESS_KEY > ${HOME}/.passwd-s3fs
chmod 600 ${HOME}/.passwd-s3fs

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

s3fs mybucket /path/to/mountpoint -o passwd_file=${HOME}/.passwd-s3fs

If you encounter any errors, enable debug output:

s3fs mybucket /path/to/mountpoint -o passwd_file=${HOME}/.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

or

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=${HOME}/.passwd-s3fs -o url=https://url.to.s3/ -o use_path_request_style

or(fstab)

s3fs#mybucket /path/to/mountpoint fuse _netdev,allow_other,use_path_request_style,url=https://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 ACCESS_KEY_ID:SECRET_ACCESS_KEY > /etc/passwd-s3fs
chmod 600 /etc/passwd-s3fs

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

Limitations

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
• inotify detects only local modifications, not external ones by other clients or tools

References

• 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 Backblaze B2, 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

• FAQ wiki page
• s3fs on Stack Overflow
• s3fs on Server Fault

License

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

Licensed under the GNU GPL version 2