I'm trying to read from a USB SSD that is connected to my Pi 4 (4GB) over a powered USB hub which should deliver enough power. There are a lot of files on it so for example when doing ls it takes a while and then starts pumping out errors that file or directory XY was not found. In the syslog I can see I/O-errors. Here is what i see: https://pastebin.com/9dNSpRKx

First I thought it was because the hub was somehow broken, but even when getting it with a new one i tested further. The error only occures when the hub, to which the drive is connected, is conntected to one of the RPi's USB 3.0 ports. Furthermore it won't even boot when something is connected to a 3.0 port.

Has anyone seen similar problems or even knows how to potentially fix it?


1 Answer 1


I have similar errors. I can boot but with longer/larger read/writes it kicks my hard drives out again and again. I have unfortunately not found a solution yet.

sudo dmesg should give you more information. Do you find something like:

[   26.655337] usb 2-1.3: reset SuperSpeed Gen 1 USB device number 4 using xhci_hcd
[   26.675456] usb 2-1.3: device firmware changed
[   26.676075] usb 2-1.3: USB disconnect, device number 4

You can check if the Pi uses UAS with sudo lsusb -t. Some hard disks do not fully support UAS. See the following link: https://forums.raspberrypi.com/viewtopic.php?t=245931

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