Seagate IronWolf 12TB mounts as 1TB -> Solutions?

Howard Brotine wrote:

The device is a NAS drive, but I'd like to use it for storage internally, if possible.

The physical drive is a NAS drive, but it doesn't make it a NAS setup. Using the IronWolf drive with the USB drive dock or internally on a supported computer just makes the IronWolf drive a regular hard drive. The NAS rating makes no difference here when it comes to partitioning, formatting, or using the drive. A NAS rated drive is built a little bit better and is able to withstand more vibrations than a standard desktop drive and a NAS drive has the TLER timeout so the drive can be used in a hardware RAID if necessary. I was getting confused by the NAS reference earlier and thought you had an actual NAS setup (networked drive setup). I do find the NAS rated drives do tend to hold up better than standard desktop rated drives.

If you want to use the drive externally, then try a drive dock or enclosure from StarTech, Plugable, or OWC, but make sure the product details mention support for a 12TB drive.

If you have an older style Mac Pro tower, then I think the 12TB drive can be installed internally. It is hard to locate details, but I did see a reference on the OWC website that those systems supported up to 18TB drives.

You can partition and format the drive with any file system the OS supports...the same as any other drive.

When you see a drive not being recognized for its full size, then it means the SATA controller on the computer, adapter, drive dock, or enclosure does not support that size drive. Or it may indicate the drive is bad.

Or perhaps the drive is used and you are only seeing a single smaller partition. Keep in mind that macOS Disk Utility hides the physical drives from view with later versions of macOS 10.13+. Within Disk Utility you may need to click "View" and select "Show All Devices" before the physical drive appears on the left pane of Disk Utility. Select the physical drive and erase it as GUID partition and MacOS Extended (Journaled). Or you can use exFAT if you need to share it with Windows. I don't recommend using APFS since it does work the hard drive harder, plus APFS tends to get errors which First Aid is unable to repair resulting in needing to erase the drive and restoring the data from backup. If you are installing macOS 10.13+ to this drive, then you will need to use the APFS file system as it is required by the OS.

If this is the device you are using, then it is not a NAS. It is just a hard drive dock connected via USB3. A NAS is a network device running its own OS which provides remote file sharing capabilities to other devices on a network.

https://www.thermaltake.com/blacx-duet-5g-hdd-docking-station.html

The product page for this Thermaltake BlackX drive dock makes no mention of supported drive sizes. Contact Thermaltake to confirm whether it supports a single 12TB drive.

If you have connected this device to another device which is sharing these drives across the network, then you omitted that very important detail.

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FYI, here is an example of some NAS devices:

https://www.synology.com

What is the exact model of the Mac and version of macOS being used? You can get this information by clicking the Apple menu and selecting "About This Mac".

Also, how are you connecting the 12TB drive? Not all SATA controllers or USB Adapters, drive docks, or enclosures support a 12TB drive. I'm guessing this is the case here since the drive is only showing as 1TB. Make sure the USB adapter/dock/enclosure supports a 12TB drive.

You're welcome.