Okay so with the end of the month approaching I've been trying to think about what route to go with the server... In particular what to do about populating it with drives. I certainly can't afford to by 4/5/6x WD Red 2/3Tb drives all in one go, but based on my understanding of ZFS I feel like there might be an optimal approach to how to do this.
The problem is that since I can't change the number of disks in the array (for RAIDZ) or buy enough disks to make the array in one go, how can I have my array but keep it upgradeable? I've currently got the following drives:
1x 250Gb (from the microserver)
1x 320Gb (from an old Dell PC I threw out years ago)
1x 1Tb (the storage drive in my current server)
1x 500Gb (in my main PC as a 3rd drive, don't use it for an awful lot)
So lets say I go out and buy 1x WD Red 2Tb to start me off... If I were to swap the 500Gb and the 1Tb over - giving my main PC access to the current storage files for transferring in the process - and then create a 4-drive RAIDZ array out of the 2Tb, 500Gb, 320Gb and 250Gb, then I'd have about 750Gb of usable space (and a lot of wasted space)... But then over the next few months I could progressively replace the smallest drive with a WD Red 2Tb and let the array rebuild, and I'd go from ~750Gb usable to ~960Gb, then ~1.5Tb and finally to ~6.0Tb when the final drive gets replaced. Does that sound right? Am I overlooking any glaring flaws with this idea? Is it bad for the drives etc?