Mixing brand model and size to upgrade storage space?

volpone wrote:

Thank you mdgm for your detailed instructions. mdgm wrote: Well you could replace two disks one at a time, hot-remove disk, wait say half a minute then hot-add again... I'm not sure to understand the hot-plug / wipe procedure. In my idea (from my 4*1TB X-RAID2 current setup) it was sufficient to add the 2 new 2TB disks and then factory reset to wipe and rebuild completely the array (after a having done a full data backup obviously).Then reinstall add-ons and restore the data backup. Where i am wrong ?

You're right. I was just mentioning the alternative where you don't do a factory reset but get 4k sector partition alignment. Hot in this case means do it while the NAS is running.

volpone wrote:

Well you could put one of the new 2TB drives in a USB enclosure and backup your data to that. Then do another backup of your most important data to your other NAS and external USB hard drives.Then do a factory reset and hot-add (add while NAS is on) the 2TB disk you put in a USB enclosure to the NAS. OK for external backup using one of the new drives, any pointer on an USB external enclosure supporting 3TB drives (i'm not sure if i'm going to buy 2 or 3 TB new disks) ?

I'm not sure. Maybe someone else has some ideas. You might want to search the forum for suggestions.