I actually have this exact use case. About 25MM files, ~20 TB total. Lot of directories. Many servers (~10), only a few that have the exact same synching file/f

I actually have this exact use case. About 25MM files, ~20 TB total. Lot of directories. Many servers (~10), only a few that have the exact same synching file/folder setup (in other words, some servers have only video, some have only code, some have it all, etc, you get it). It works... pretty well. I won't lie and say it works perfectly with all of our other file utilities and scripts we run, but 95-97% of the time I never think about it. I use it with SyncTrazor on Windows Server deployments as well as Debian servers and yeah, I could be happier, but I highly doubt there's anything out there that can beat SyncThing overall. Just know that with that many files the initial scans and DB building will be brutal, and the periodic syncs and rescans will be taxing. Highly recommend getting cheap 1-2U servers with dual sockets and lots of cores/threads - multiprocessing goes a long way in doing the file hashing. EDIT: I will add that I only use it on servers and not on any client/desktop machines, so I can't vouch for its use there.