is this possible with freefilesynch?

[rgs]

I want to synch my files but not sure how to do this.

I have one large drive 20tb that is basically a backup of 5 other drives.
One on one mirror image is easy.

I am not sure if this is an option

compare each backup drive to the master drive, if the backup has something the master does not it can be deleted(not sure how to actually do this yet but I do think its an option not to add missing files just delete stuff not on the master drive).

Assume that can be done, the next part may not be possible. Every time the master drive it compared to a backup drive it keeps a list of what was not on the master drive on a list within the program. For example it checks the master vs backup 1 drive. It deletes files from backup that's not on the master. it also keeps a list of files on the master vs backup 1, say it detects 1k files. Then step two master vs backup 2, does the same thing deletes anything not on the master except this time it compares what's on the master to the back up 2 and removes everything on the list it created before, so for example after backup 2 the list goes from 1k files to 700 files, and keeps doing that. Then the master and final backup does it thing and then the list say it down to 100 files.

at that time you can throw those files on one of the backup drives and then everything on the master is on the backups somewhere.

Is this an option to do or even if it can only show what's not on them on a list and having to manually copy them to a back up.

Thanks,
Ryan

[Flowers4]

Sounds like what you need is a true backup solution rather than a simple sync.

Check out Kopia. It's open source, works on Windows Linux and Mac. You set a schedule for it to check for changes in the data say every 30 minutes. If no data has changed it doesn't do anything.

The big benefit for you is it handles deduplication for you automatically.

You can back up data from 10 different drives and the backup repository will only store one copy of each file. If you have duplicate files in your data you will not have duplicate in your backups with Kopia.

Syncing will blindly back up duplicate data multiple times.

I still use FFS to handle syncing of my data between Cloud drives.

Kopia and FFS have different strengths and thus they are both Worthy. Use both i say.

[rgs]

Well my issue is for the backup of the one drive is spread among 5 drives that I can only connect one or two to the pc at a time. all my other drives have the exact same drive as a backup so making them mirror each other works fine.

Hopefully someone has a solution for this for this program but I will check out kopia as well