You can go to the maximum available 18TB per disk.

Yes, under Linux Debian the drives in the FANTEC QB-35US3-6G can be displayed and mounted individually so that a software RAID can be created with `mdadm`. - The enclosure supports up to four SATA I/II/III hard drives, each of which can be used, replaced or expanded separately. - Debian, like other Linux distributions, supports the use of multiple hard disks and enables the creation of software RAIDs with `mdadm`. It is important that the system and the hard drive controllers support the use of hard drive capacities, especially when it comes to larger hard drives. - As the enclosure does not provide any RAID functions internally, but only provides the physical accommodation and connections for the hard disks, a software RAID can be set up under Debian without any problems.

There is no space limitation. So no HHD size limit. You can have 88 tb if you use 22 tb hdd drives for example.

I run the product on a media server with a Debian-based operating system (OMV), so very similar to Ubuntu, which is also based on Debian. Works fine, the hard drives also go into standby by themselves when not being accessed. I think the automatic power on/off works together with the system, but I'm not 100% sure because I usually leave the system on all the time. The only thing that gives me problems from time to time is that the Fantec case doesn't switch itself on again after a power failure, but this is probably a very specific problem that will be irrelevant for most people and only occurs very rarely. It also has nothing whatsoever to do with the operating system. By the way, I would recommend replacing the standard fan with a better one, because the built-in one is not very quiet. I installed a suitable Noiseblocker 80mm fan, and now you can't hear the device anymore.

The housing is not particularly loud. However, it is not very decoupled. In my case, it's on a wooden plate, and that passed on some noise at the beginning. In the meantime, I put 2 cm of rubber under the feet, and since then practically nothing is audible. The fan is quiet enough. You can set 3 levels and there is also an automatic control. If the data transfer is high for hours, the fan gets a little louder (and then audible). After almost 2 years of operation, the fan on one of the two units has become a little louder (bearing) and I will occasionally replace it with a (quiet) replacement fan. I find the enclosure to be sufficiently well constructed and reliable. There have been no failures despite 24/7/365.

There is also a version with a RAID controller, where a RAID can be configured and displayed as "1 hard disk" or disk storage. (Unfortunately, I also got this version and hope to spare you the same fate with this answer ;-) )

Since I change the hard drives for each project, I have not screwed on the handles. Works wonderfully. But it is important to shut down the units before changing the hard disks.

Found the answer: FANTEC QB-Bracket 25 QB-Bracket 25 2,5″ to 3,5″ adapter for the installation of a of an SSD or 2.5″ HDD

I have 2 8TB disks. They are even put in slots 1 and 3 and they work perfectly.

Hello.. According to the manufacturer's manual, a maximum of 4x6TB can be installed. Greetings

2 3.0 TB WD Red (NAS Hard Drive) , 2 6.0 TB WD Red (NAS Hard Drive). Fantec is connected to the computer via USB 3, the computer is not connected to the internet, and I only back up my image files manually. Fantec is very quiet and cleanly manufactured.