Troubleshooting continuous Sync errors

In continuous mode, Sync can encounter operating system-related issues. The following article describes how to fix several of these errors.

Error returned when you attempt a continuous synchronization

If you attempt to run a continuous Sync from a client that does not support continuous mode, you receive the following error:

Failed. File system change notification not supported by platform (code=45112)

If you attempt to run a continuous Sync to a server that does not support continuous mode, you receive the following error:

Failed. [PEER} File system change notification not supported by platform (code=45112)

Solution: You must run your Sync session to or from a computer with an operating system that supports continuous mode:

Continuous Sync direction Supported Sync client OS Supported Sync server OS
PUSH Linux, Windows, macOS All
PULL All Linux, Windows, macOS
BIDI Linux, Windows, macOS Linux, Windows, macOS

If that is not possible, you have two options for a workaround:

  1. You can run async as a cron job that detects file system changes with asperawatchd. For more information, see Starting Aspera Watch Services and creating Watches.
  2. You can run async in continuous mode on source systems whose operating systems do not support file notifications by using --scan-interval. This enables periodic scanning of the file system to detect changes. The periodic scan is less efficient than the Aspera Watch Service file system monitoring.

Error returned when you attempt to monitor a Linux directory in continuous mode

If you attempt a continuous async session and the source is a Linux computer, you might receive the following error:

Failed to set up directory change notification - reached the per-user limit on number of inotify watch descriptors.

Cause: You have exceeded the per-user limit that is imposed by the OS on the number of directories that can be monitored (determined by the number of inotify watch descriptors).

How to recover: You must modify the kernel parameters on the Linux computer to increase the maximum number of user watches. The following procedure might differ between Linux versions; consult your operating system Administrator's guide for more information.

  1. On the Linux computer, open /etc/sysctl.conf in a text editor and increase the maximum number of user watches. Enter a value that exceeds the maximum number of directories that are ever expected to exist in the docroot that is monitored by async. For example,
    fs.inotify.max_user_watches=1000000
  2. Save your changes.
  3. Load the configuration changes by running the following command:
    # sysctl -p 
  4. Confirm that the changes took effect by running the following command:
    # sysctl -a | grep max_user_watches  
    fs.inotify.max_user_watches=1000000