danky wrote:Is the same output as fdisk -l from ssh
danky wrote:I can backup all data and start from zero, maybe is the best for have DR from start and 8k aligned sectors, right?
Probably would be a good idea if you have the time. You'll need 4k sector alignment eventually anyway (even if not choosing 4k sector 2TB disks now) and a backup and factory default may well be quicker. It'll also give you a clean setup on the latest firmware. If you look in initrd.log and see that you last factory defaulted before 4.2.11, then the move to native EXT4 from a factory default (on 4.2.11 or later - obviously you'd stay on the 4.2.16 beta firmware or use the production firmware if that is available by the time you wish to do the factory default) is a nice bonus. Native EXT4 allows for file sizes greater than 2TB, with a limit of 16TB. It has other nice benefits too.
You may wish to do a System > Config Backup (keep zip file) before the factory default, then restore the Config Backup (zip file that was downloaded) afterwards.
danky wrote:I would use this setup: 2x0.5TB, 2x1.5TB, 2x2TB
So I guess I will have 4TB until i change the 0.5TB with 2TB disks
Yes, before overheads and also allowing for disk manufacturers considering 1 KB = 1000 Bytes, whereas NAS (like most other computers) considers 1 KB = 1024 Bytes. You would only need to change one of the 0.5TB disks with a 2TB disk to expand your volume (another edit: it would of course be treated as a 1.5TB disk until you had a fourth 2TB disk in your array).
Edit: One should note that to get 4k sector alignment you can swap hot-remove one disk, then hot-add it and wait for the resync then repeat for the next disk. This is very time consuming (more so than a factory default) and shouldn't be attempted if you don't have a good backup. Also as I said earlier I don't know if 4k sector alignment is required or not for a migration to dual-redundancy.