Comparison of Aspera File Delivery and Synchronization Tools

Your Aspera product includes several transfer tools that can be used for automatic file delivery and synchronization.

Hot Folders: a Windows-only, GUI-managed automatic file delivery tool.
Watch Folders: an automatic file delivery tool that is easily managed by using the GUI, Console, or the Node API.
Aspera Sync: a multi-directional synchronization tool for when complete file system synchronization is required.

	Hot Folders	Watch Folders	Aspera Sync
Supported platforms	Windows only	Windows macOS Linux AIX Solaris Linux on z Systems BSD	Windows macOS Linux AIX Solaris Linux on z Systems BSD
Additional license required	No	No	Yes, a Aspera Sync-enabled license is required on both endpoints
Interface	Aspera desktop GUI	Aspera desktop GUI, Node API in any command line, command line on the Aspera client, or Console web UI.	Aspera client command line, Console web UI for management only (no creation)
Client applications	HSTS and HSTE	HSTS and HSTE	HSTS and HSTE Drive
Server configuration required	No	No (only need asperawatchd on server for pull Watch Folders)	Recommended
Create in Console	No, but you can monitor transfers	Yes, you can create, monitor, and manage	No, but you can monitor Aspera Sync jobs and their associated transfer sessions
Transfer modes	Client to server (push) Server to client (pull)	Client to server (push) Server to client (pull)	Client to server (push) Server to client (pull) Client and server (bidirectional)
File delivery or synchronization	File delivery: Files and folders added to or modified within a Hot Folder on the source are automatically sent to the destination folder. Files deleted from the source are not deleted on the destination.	File delivery: Files and folders added to or modified within a watch folder on the source are automatically sent to the destination folder. Files deleted from the source are not deleted on the destination.	Synchronization: All file system changes (additions, deletions, and modifications) are synchronized from source to destination (push or pull) or synchronized between source and destination (bidirectional).
File system monitoring	Windows operating system notifications.	File system snapshots collected by asperawatchd.	In continuous mode: file system notifications In scan (on-demand) mode: Aspera Sync scans the file system on the source side and compares it to the Aspera Sync database asperawatchd
Transfer schedules	Immediate (as soon as a file system change in the Hot Folder is detected) On a user-specified schedule	Immediate (as soon as a difference between snapshots is detected)	Immediate (in continuous mode or when using Aspera Sync with asperawatchd) On a user-specified schedule (Aspera Sync run as a cron job)
Growing file support	No	Supported on HSTS, but not for object storage	No
Database space requirements	None	At least 2 GB free per 1 million files, 3 GB free per 1 million files on Windows	At least 2 GB free per 1 million files, 3 GB free per 1 million files on Windows
Best for	Automatic push and pull delivery with a simple GUI interface that does not require Console	Automatic push and pull delivery with a simple GUI interface that does not require Console Managing and monitoring push delivery through Console	Precise synchronization between two endpoints of all file system changes (including deletions) Bidirectional synchronization Very large file sets - up to 100 million items across thousands of directories
Limitations	Windows only GUI must remain open In pull mode, pull files even if they are in use	Transfer rate of millions of small files can become limited by the speed at which database metadata can be written	Continuous mode available only for Windows and Linux sources Transfer rate of millions of small files can become limited by the speed at which database metadata can be written
More information	IBM Aspera High-Speed Transfer Server	Introduction to Watch Folders and the Aspera Watch Service	Introduction