New NAS and Volume/Disk downsizing

[jubox]

Hi NAS wizards,

I’m about to embark on an upgrade project with some foreseen complications for which I could do with some advice.
My current setup is a 2-bay QNAP NAS with 2x8TB drives in RAID-1 configuration. My drives are good but too loud and I quite fancy upgrading to something bigger and more modern.
I’m upgrading to a 4-bay unit (ts-453d) in which I’m putting 4x6TB drives in RAID5 configuration. WD Red+ drives of that size spin slower (but still fast enough for my needs) and under a RAID5 configuration offer the best volume space vs. Cost balance I feel.

Anyway, I’m not sure how to go about replacing my drive – I keep reading that downsizing is not possible/easy – even though there’s only 3TB worth of data in my current volume.
I’ve been thinking about a couple of options, and wondered if you guys out here have any thoughts about it, or other ideas:

• Option 1: Put my 2 old 8TB drives in my new 4-bay NAS and create a separate volume with 1 or 2 of my new HDDs, transfer my files, then replace the old drives with the other two new ones and set up the RAID5 configuration (having never done it, I’m not sure this is possible not what the unforeseen complications are)
• Option 2: Just plug one of the new drives externally (I have a little adapter I can use for that) and use it to transfer files to my new NAS (with the three other drives in)
• Option 3: run the two NASs in parallel with their respective drives in and at the same time, and transfer the files over the LAN

Any thought and tips would be most welcome.
Thank you all.

[Thisisnotmyname]

option 3: set up the new NAS then transfer the files NAS to NAS once it is complete

[jubox]

Thanks. Do you know if there's any way to save/transfer the NAS configuration as well?

[Thisisnotmyname]

Not automatically but the config itself of the NAS rarely changes once you have it set up so just use the backup/restore section in the settings app to back it up manually when you make a change.