I need some advice on how to set up my backup.
I have an internal data disk (6 TB) that I would like to back up regularly to two backup disks (3 TB each). Mirroring is enough, I don't need a history. The backup disks are installed in hot-swap trays and are stored elsewhere when not in use.
I would prefer to just slide the trays in to start an automatic backup. When it's done, I get an email and just pull out the disks.
I was looking for a ready-made solution, but I couldn't find one. The USB backup plugin can only be used for backups to one single hard disk. So I'll probably have to write a script.
Problem 1)
I don't want to manually split the internal hard disk data between the two external hard disks. I was thinking about using the Unionfilesystems plugin to merge the external disks to one file system. Are there better alternatives (raid)?
Problem 2)
Hot plug. On hardware level, the hot-plug already works, I can plug in and use the disks during operation. How can the hard drives be safely removed? Just pulling it out is certainly not a good idea neither for a raid nor for a unionfs. So how do I unmount them?
Problem 3)
The simplest part: copying the data, I would use rsync for this.