ExpanDrive runs on Microsoft Windows 7 and newer (including 64-bit and Windows server installations) as well as macOS 10.10 or newer.

All old versions of ExpanDrive are archived for download here, along with release notes:

• ExpanDrive for Mac
• ExpanDrive for Windows

Most SFTP servers do not give us any way to determine how much free space the user has available. On these servers ExpanDrive uses a dummy value. ExpanDrive does correctly report free space when connected to servers that support the statvfs@openssh.com command, such as OpenSSH 5.1 and newer.

Privilege escalation is a feature we have looked at in the past, but there is unfortunately no way to implement it safely and transparently across the variety of different SFTP platforms available in the world. Because SFTP (and FTP too, for that matter) lacks any built-in command to change the UID assigned at connection time, the only way you could even approach this problem would be to invoke shell commands. We’ve experimented with doing this, and concluded that it’s just too error-prone, fragile, and potentially dangerous to justify the complication. You can, of course, connect to the server through ExpanDrive as the root user, and gain administrative access that way.

We love this idea, and we’ve spent a fair bit of time trying to make it happen. Unfortunately there are some filesystem characteristics that time machine relies on [hard links, notably] that we can’t safely emulate with ExpanDrive. It’s also fairly slow on high latency connections.

ExpanDrive does not create new .DS_Store files on the remote server. When the system requests creation of a new .DS_Store file, we make a memory-only object within ExpanDrive to represent it. When the drive is disconnected, these files and their contents are dropped. However, if an existing .DS_Store file is found on the remote server, reads and writes on that file are performed normally.