How to copy/move from> to> another SSD

Good morning everyone,
So I would like that backup a file to one of my internal SSD’s. I have it mounted, I have it added to the “Domain”. I want to move it from a “Domain” to the other internal SSD so I will have to copy/cut and paste to the folder inside of this SSD. Obliviously “click & drag” doesn’t work,LOL. But I can’t copy/paste this file to the other internal SSD. I do the (ctrl+shift+c) to copy…I see the clipboard popup and then I do the (ctrl+shift+v)…I see the clipboard popup. Then I go to the other internal SSD to paste and NOTHING!! Paste isn’t a option.
How do I do this…Move a file from a “Domain” to another internal SSD so I can have backups?

Mind you these other SSD’s are part of my SAS raid drive card and I can see them,mount them, copy from them to the Qubes desktop BUT I can not copy/move from Domains to them,Why???

Or maybe I’m done omg this hole process wrong. Can someone explain or help out?

Also for security reason I have the ability to power these internal SSD’s on/off. So once I’m done doing anything I need to do they are off. So when they are off the computer let alone Qubes doesn’t even know they exist, of course until I power them on again. And this powering on/off of these internal SSD’s is done by “hardware” not “software”…

I figured out what I could do…I will have it “screenshot” stuff. That’s the only way I can save from dom0 to these internal drives.
But I can’t view whatever I have saved to that drive… Right click on it, "open with other application, chose application and nothing…

So my question is…
Why “attached” other internal drives to active (appVM’s or templates) if I can’t access/use them??

After I mount the other internal SSD. I go up to the right corner and click the icon, hit the plus sign to attach his drive,it attaches. Then I see displayed…
dom0:sdk1 - Samsung_SSD (drive name) (debian-10). But I can’t do anything move,copy,paste to it from Domain,Template. So what is the purpose of this feature??

Did you try to follow this guide: PCI Devices | Qubes OS?

No but I’ll take a look at it,thanks

Ok so I read this doc and I still have problems trying to attach a USB SSD. I know what USB controller it is but still no go. So someone here can explain what and why and how as it isn’t covered in the docs.

So I go to devices in the Domain I want to attach this USB SSD to. Find the USB controller. Click and move it over. I then get a “You’ve enabled dynamic memory balancing, some devices might not work”. OK, I increase my memory from default (400) to (2gb). Still get this error, ok then, I just click “apply”…nope…Now I get this
ERROR : Devices tab:
Can’t attach PCI device to VM in pvh mode

I figured it out after a week…

Perhaps:

Thanks deeplow, only took me a week to figure out… LOL

But I have NO keyboard now. Only the mouse works.

The keyboards doesn’t work on ANY usb port. Even the one where the mouse works on. Dead in the water now!

Forgot to enable it…Yeah I f***** myself on this one

Any fixes besides ‘reimaging/rebuilding’. Which I maybe should do with a faster SSD