I had two drives on my Raspberry Pi 4 B and they kept being unmounted, I moved one to my router and it seems to be working fine now...
I read about max_usb_current=1 doesn't make any difference on Raspberry Pi 4 B, but is there any chance I could put lots of drives on my Raspberry Pi and have them stable? I'm using the official power supply.

  • 2
    Read this bit on powered hubs.
    – Seamus
    Feb 11, 2020 at 19:15
  • Like @Seamus said, try to use a powered hub. Make sure it's been tried before as I've had trouble with a couple myself
    – user96931
    Feb 11, 2020 at 20:34
  • You can't run two usb powered drives on an Rpi 4. The current limit is 1.2 A shared between all USB ports, and one drive alone will take up to 1 A on spinup and maybe on seek, so you do the arithmetic. I tried 2 drives and got the same thing, and then I read the spec. Feb 11, 2020 at 22:47

1 Answer 1


As others suggested, the problem was that there wasn´t enough power to feed 2 hard drives, so using a usb-hub with power adapter solved the issue

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