Transmit Disk

What’s The State of Transmit Disk with Transmit 5?

Short answer: Transmit Disk behaves exactly like it did with Transmit 4 when used alongside Transmit 5, but does not include any of the new cloud providers or speed enhancements delivered in Transmit 5.

Transmit Disk supported Server types

  • Amazon S3 (V3)
  • FTP
  • FTP with Implicit SSL
  • FTP with TLS/SSL
  • SFTP
  • WebDAV

Troubleshooting Transmit Disk

If you’re unable to connect to a Server via Transmit Disk the first recommended troubleshooting step is to perform a regular connection through the Transmit app.

If the problem persists after confirming that you are able to connect through the Transmit app, please check if the Server configuration is listed under either of the unsupported server or unsupported configuration sections below.

Unsupported configurations

  • Amazon S3
    • Files larger than 5GB in size
    • Regions that require V4 auth support: (Frankfurt, London, Montreal, Mumbai, Ohio, Seoul)
  • Servers that are not included in known_hosts or that have had their host key change since the last connection
  • Servers without a saved password (Ask on connection)
  • Servers that use SSH keys that are stored in Transmit and/or Panic Sync

Unsupported Servers

  • Amazon Drive
  • Backblaze B2
  • Box
  • DreamObjects
  • Dropbox
  • Google Drive
  • Microsoft Azure
  • Microsoft OneDrive
  • Microsoft OneDrive for Business
  • Rackspace CloudFiles

Technical details and the future of Transmit Disk

Transmit Disk is built on a macOS technology called Kernel Extensions to run and integrate with the Finder. Kernel extensions are designed to add functionality to macOS from the lowest, most privileged levels.

In recent years Apple has started to restrict kernel extensions for increased user privacy and system stability. As of macOS 10.10 Yosemite, kernel extensions must be whitelisted and signed by a special certificate from Apple which is not automatically available to all developers. In macOS 10.13 High Sierra, each kernel extension must also be directly whitelisted by the user from within System Preferences. There have been rumors that post-High Sierra, Apple might restrict the availability of kernel extensions even further.

Additionally, the way the Transmit Disk kernel extension works with Finder is highly synchronous (meaning responses from connected servers need to be fast). The newer cloud-based protocols in Transmit 5 are based on web technologies such as REST and are, by nature, more high-latency and asynchronous than a protocol such as SFTP. This means that integrating these protocols into Transmit Disk’s current architecture is more difficult and prone to errors. From within a kernel extension, running at the lowest layer of the system, an error can sometimes completely take down macOS (the so called black screen of death) requiring a system restart.

After speaking Apple about all of this, they offered several recommendations for transitioning Transmit Disk to a different architecture that would allow it to integrate better into Finder and the system. While these leads are promising, it does mean a fundamental rewrite of Transmit Disk itself would be required.

Due to this, we did not schedule development of a completely new Transmit Disk alongside our development of Transmit 5. Instead, we opted to make sure the current Transmit Disk worked well alongside Transmit 5. We understand many users love Transmit Disk and would like to have its features available to all of the new cloud providers in the future. As such, we are investigating a new Transmit Disk architecture that would allow all of the wonderful speed and protocol improvements of Transmit 5 to be accessible directly from your desktop. It might just take some time.

Last updated February 1, 2017