Why does my Drobo 5C (5x3tb) as having 70.37tb?

For some reason all of the three Drobo 5’s I have in operation in the USA and Germany report their total available space incorrectly. Each one is connected to a different computer in their respective places (LA - iMac 27, SF - rMBP 2018, Berlin - iMac5K), and all report huge amounts of available space, when in reality they have about 12tb total capacity and maybe 3-6tb available. Drobo Dashboard reports correctly, but the macOS Finder does not.

Why does this happen, and how to fix it?

Could it be thin provisioning?

If I recall from the time I set it up its because the Drobo capacity can be increased on the fly as your HDDs fill up (by upgrading your HDDs). The capacity reported to/by the OS is essentially a placeholder.

But I need to know from Finder what the actual usage and remaining space of my Drobo is. There must be a way, or is there not? :-/

Im sorry haven’t managed to figure out a way to do that. For me its a bit easy as its only one Drobo and I have a handle on the usage. But I can see how it would be frustrating for you.

Thanks for checking in, anyway, brother!

Drobo doesn’t use the file management format that Mac (or PCs I think) so the reporting back to the OS is always the maximum volume allocation that the Drobo firmware is setup for. This has always been the characteristic of “Beyond Raid” since the beginning of Drobo. By hiding the actual volume size from the OS the user can willie nilly swap out and add/subtract drives with no consequence to the OS (OS thinks the volume is still at the full size the Drobo firmware presents itself as).
In the meantime the user must use Dashboard to find out what is really going on in the actual array. By using Dashboard’s “capacity” and “volumes” buttons you can “back calculate” your real capacity and remaining space. Yeah kind of a pain but that’s how it works…

Thanks for the clarification. I was already beginning to think that it was a limitation such as this.
I’ve been using unRAID for over 15 years, which also allows users to swap out disks at will (as long as they aren’t larger than the parity drive(s)), but unRAID is a much more sophisticated system and can share out in pretty much all standard networking formats which report storage correctly, but it isn’t a DAS such as Drobo, so it’s a different animal.

Ok, well, now that I know what not to expect from Drobo, I know what to expect. Thanks!

No problem. I’ve always thought of the “man behind the curtain” scenario with Drobo. When they came out in the late 90s with this technology it was revolutionary, but now, meh… Good luck!