Using the Aspera Watch Service with Aspera Sync Aspera Sync can use asperawatchd for more efficient file system change detection, particularly for file systems with many files. Starting Aspera Watch Services and Creating Watches The Aspera Watch Service (asperawatchd) is a file system change detection and snapshot service that is optimized for speed, scale, and distributed sources. On file systems that have file system notifications, changes in source file systems (new files and directories, deleted items, and renames) are detected immediately, eliminating the need to scan the file system. On file systems without file notifications, such as object storage, Solaris, AIX, and Isilon, file system scans are automatically triggered. Starting the Aspera Watch Service Aspera Sync can be configured to use asperawatchd for fast synchronization of very large numbers of files without scanning the directory. Aspera Sync can push files from a local directory, pull files from a remote directory, or create a bi-directional session between two directories (as long as asperawatchd is properly configured to monitor both directories). Watch Service Configuration The Aspera Watch Service configuration in the <server> section of aspera.conf includes the snapshot database, snapshot frequency, and logging: Aspera Sync with Aspera Watch Service Session Examples Examples of async commands for push, pull, and bidi sessions that use asperawatchd to identify files to transfer.