Generally no, Free File Sync is a program you install to your local computer. The confusion stems from your use in your first post of: a "Sync" backup job. Are you using Safepoint / Backup to backup the My Cloud to the attached USB hard drive? Or are you using WD Sync to sync or backup your computer to the USB hard drive attached to the USB port on the My Cloud?
A “sync” and a “backup” are two slightly different tasks that accomplish slightly different end results.
If one is using Safepoint / Backup, one can instead use Rsync to copy files/data from the main My Cloud drive to a USB hard drive attached to the My Cloud. Use the forum search feature, magnifying glass icon upper right, to read through the other discussions on using Rsync on the My Cloud. Here is one such discussion:
https://community.wd.com/t/happy-accident-includes-an-alternative-to-safepoint/96152
There are numerous complaints about the slowness of backing up to a USB hard drive attached to the My Cloud. Start with the following discussion on slow copying speeds:
There are other options mostly for the older gen 1 v4.x My Clouds, which include using an alternate OS (clean Debian) on the My Cloud that may provide better copying speed between the USB port and the My Cloud hard drive.
https://community.wd.com/t/clean-os-debian-openmediavault-and-other-firmwares/93714/1058
If one is using WD Sync, one can use Free File Sync (http://www.freefilesync.org/download.php) instead, which more than a few here have done, due to the various issues some are having with WD Sync.
Just a general comment on copy speeds. One almost never gets the advertised copying speed either from a computer to the My Cloud or from the My Cloud to an attached USB hard drive. The reasons are numerous and include the slow/low powered processor used by the My Cloud and the hard drive speed/hardware used by both the My Cloud and the USB hard drive or computer. One can use various methods to test the copy/transfer speed to or from the My Cloud to get a feel for the actual transfer speed. Also note that typically, depending on the backup or sync being performed the first backup or sync is always the slowest and takes the longest amount of time.
