Best or system-kindest way to copy my old QNAP's data over to my new QNAP NAS

[Enquiries]

Hiya! 1) Mid-Sept is long gone. Is the message above these boxes still current?
2) I run a TS-889 Pro with 6x WGST 4Tb HDDs, set up in RAID-6 to yield 16Tb of storage.
3) I'm looking to get a TS-664-8G NAS populated with 6x WD Red 8Tb HDDs, configured in RAID-6 to yield 32Tb of usable storage (my budget forbids anything larger).
So to my question:
Once I've purchased the TS-664, populated it, configured to RAID-6, and connected to my 16-port passive Gbit switch (along with the older 669):
** What is the best way to copy ALL of the data on the old 8Tb NAS to the new 32Tb one? **
By best, I mean: most efficient, error-free, and most importantly, avoids overstressing either unit - especially the older NAS, whose age (and slowly increasing fan noise) has prompted this upgrade.

Bonus question: have you guys ever done a video on REPLACING FANS in an aging QNAP NAS? Would love to see one! Assuming the sound isn't the actual HDDs or the power supply unit's fan!
Thx Agarthan

[Ekky]

Hey there,
1. It's a good practice to check if the info is still current, especially in the fast-paced tech world.
2. Your RAID setup sounds solid!
3. To copy data, use the QNAP's built-in file transfer tools for efficiency and minimal stress on the units.

[Agarthan]

Yes, but *which* "built-in file transfer tool"? ...there are a bunch, as you highlighted in a recent video on your YouTube channel.

This will be a one-off copy of all NAS files from one big unit to another. No scheduling or complex setups are likely to be needed - just the best software tool from those QNAP makes available.

So - any tips on which one that would be?

HBS3? HybridMount? Qsync? Just copying stuff between both NAS units via SMB using good old Windows Explorer?

That last option is deffo the one requiring the least thought by a typical Windows user such as me (though I also run Linux Mint and pretend i know what I'm doing), but I imagine dragging literal terabytes between SMB-mapped drives is not the preferred way to go - nor the one that will be kindest on my [likely overworked] WD Reds!

Can you please say what method YOU would use - especially if certain folders were more precious (e.g. family photos and videos) and thus a priority to copy over than others?

P.S. I intend to never connect either NAS to the internet. It's just better to be sure

Thanks again, Agarthan, Oz