I've got a couple of external 4TB HDDs that are mirrors of each other for my backup, and they've always been in HFS+ as I've been a Mac user for a long time. However, I have no use for Mac computers anymore and have recently moved back to Windows, but the drives are keeping me from getting rid of the Mac.
I need to convert them from HFS+ to NTFS, but I'm very concerned about losing the data or parts of it being damaged in the process. I currently only have two drives that are 100% mirrors of each other, and no other medium which could temporarily hold the entirety of this data. I would have to wipe one to convert to another, which increases the chance of data loss immensely. I'm worried I will have to buy more drives to be safe, so that one of them is completely untouched by the process.
My main issue comes from the actual process of copying the data, I'm unsure what the best software or method to copy the data is. I see recommendations for Tuxera and Paragon, but especially with the latter I read a lot of sketchy stories of data going missing or outright corrupting. If I tried to do the conversion in Windows, I would have to be certain that the drive cannot be touched by antivirus, as I already know some of my files will be flagged as false-positives. I can't afford this, and for 4TB the drives are EXTREMELY data dense. Not sure how to verify that the NTFS drive will be a 1:1. Just looking for some pointers as to how to most safely go about this process as it's causing me a lot of stress at the moment and holding things up.