I've been very interested in and planning on using BitTorrent Sync to keep my family files synced between our different households. Here is my previous setup. Central Linux File server with 2 HDDs in RAID 1. I've been using that setup for a number of years now. Starting with the day when I thought that RAID was a backup solution. I am now aware that it is not a good backup solution (at least by its self) Planned setup: Primary server at Location #1 with RAID 1 mirroring (Linux)Secondary 'Server' at Location #2 with a single WD Red drive. Basically a 24/7 workstation (Win 7)Tertiary 'Server' at Location #3. Essentially a low powered NAS device at that location. Investigating a RaspberryPi. This location is planned for but not guaranteed at this point. Those three nodes will sync all the data. There will be several other nodes (laptops, other workstations, smart phones) that have separate sync profiles to sync only a subset of the files (Just pictures or music, or a folder specific to an individual (family member). Main question: If I'm syncing this between three (+) nodes how important is it to have RAID on the primary server? Other question: Is there any problem with my sync strategy? Ie. All data synced between three nodes and then smaller sync profiles to sync specific sub directories with "second level" nodes like laptops or phones? Possible case for sync conflict? Hypothetical: Location #1 which houses the primary server also has User #1 which has a laptop and smart phone. User #1 wants his Music files to sync to his laptop, phone, and server network but doesn't want all the pictures on his laptop or phone due to obvious storage space limitations. There is already a profile on the Primary Server to sync the root directory of the data drive but he sets up a second profile to share the Music directory (sub folder of the Root profile) to share it to his Laptop and Phone. Will any issue arise? PS. I'm aware that just as RAID isn't a backup solution on it's own neither is BitTorrent sync. A corrupted or deleted file (be it by a virus or user it doesn't matter) will propagate across all nodes as well. Just at a slower speed than RAID. So unless an error was detected quickly enough to take a node offline it would still sync. I will be using a second service (such as Crashplan or similar) to make a regular incremental backup from one of the 3 main nodes to a second HDD in one of the other three nodes so that there is a true offsite backup of the data.