S3QL 是个用来在线存储数据的文件系统，支持 Amazon S3 、SFTP 服务器等。
S3QL 1.7 改进内容：
- Metadata is now stored in a custom, delta-encoded binary format, and inodes are assigned sequentially and not reused.
- This makes S3QL fully NFS-compatible.
- s3qlcp now also copies extended attributes and no longer generates incorrect block reference counts when copying a file which has identical blocks.
- This release eliminates a race condition in s3qlcp.
- When copying a file with s3qlcp immediately after it was modified or created, it was possible that s3qlcp would copy the new file attributes but the old data blocks.