s3fs

s3fs allows Linux, macOS, and FreeBSD 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, 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
  

• Arch Linux:

  sudo pacman -S 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 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 10.12 and newer via Homebrew:

  brew install --cask macfuse
  brew install gromgit/fuse/s3fs-mac
  

• FreeBSD:

  pkg install fusefs-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:

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)

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

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 object, optimized with multi-part upload copy
• metadata operations such as listing directories have poor performance due to network latency
• non-AWS providers may have eventual consistency so reads can temporarily yield stale data (AWS offers read-after-write consistency since Dec 2020)
• 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

• CSI for S3 - Kubernetes CSI driver
• docker-s3fs-client - Docker image containing s3fs
• 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