I want to backup my NAS (currently one folder around 5tb, one about 1tb) to external drives. I tried using
gnutar (installed using
homebrew) which in theory does what I want, but it can't update the TAR after first creation. I have to re-create it everytime. Also, I'm having a hard time trusting that TAR archive if something simple as update fails with an obscure error message.
Other solutions I saw included mounting all external drives at once and creating a large volume, then use
rsync to keep everything in sync. This is the solution I'm leaning towards, but it also feels a little fragile.
Simply copying files until the disk is full, then requesting the next disk would be really great.
I looked at various backup solutions (e.g. Carbon Copy Cloner), and none of them could copy one large source folder to multiple volumes.
I'm having a hard time believing that I'm the first to encounter this problem, hopefully you can help me and my weak Google-fu out.