rpi 4 with external hdd enclouser issues

hi
i got my new rpi4 4gb and i have an external hdd enclouser with 2 hdd inside.
when it was connected to the rpi3 - they worked great with no issues.
now, its a big mess.

first, i created a new sd card for the pi with the newest version of dietpi and installed very few apps i use.
then connected the external hdd and mounted them.
reboot.
they are not mounted.
mount them again. they work. reboot.
they mounted ok.
try to move files with filezilla (FTP) - after 2 files successfully uploaded - all rest failed.
why?? because the hdd are disconnected.
they are not recognized anymore so i have to reboot.
after reboot - not mounted so i mount them again.
after few minutes they disconnect again. so i disabled the spin down timeout.
all the proccess of reboot and mounting again.
its still disconnects and i have issues with this.

im starting to feel sorry i switched from rpi3 to 4.

what can i do? what can be the issue?
i need the hdd’s to work flawlessly because i access them all the time and sometimes not from home and cant reboot everytime and mount each time i reboot.

please help.

It’s obvious that they aren’t getting enough power. If you are running a RPi 4 then you are hopefully using a 5V fan otherwise you will have temp issues. Well that plus 1 other 5V HDD, plus the CPU and RAM is basically maxing out the voltage that your RPi 4 has. You are asking the RPi 4 for too much current. Look at your AC adapter dude…

It’s 5V, 3Amp (hopefully not more, not less and hopefully you are using the official one). How many 5V things do you think you can connect to it and expect them to run?

You need to get a powered USB HDD hub, but then comes the problem that some of them can feed back current into the Raspberry Pi 4 and damage it or cause all sorts of bad issues. Either get a single and larger HDD that is powered only via USB, or get a real storage server.

The external hdd i have is powered and as i said worked great before with rpi3.

Why you dont think its a sw issue?

I do have the official power supply for the rpi4.
I do not have the fan yet but the pi is open with no case until i get it.

I will try the same sdcard in the pi3 and it will check the sw.
If the sw will work ok with the pi3 with the current config and hdd so its a pi4 issue and maybe the heat or usb issue.
If its wont work with the pi3 so its a sw issue for sure.

Ill update soon.

Update

Same sdcard in pi3 with same external hdd is working great.

When uploading with ftp almost all files are uploaded, no disconnection of the hdd.

So the sdcard and the dietpi is ok at least with pi3.

Either its a compatibility issue with pi4 and dietpi, or heat issue, or usb issue with the pi4.

What do you think?

No one can be sure, but you should never run the RPi4 without at least a heatsink, and you should get a fan. I would not expect anything to work normally without one.

Temperature is an issue. I run a Rpi4 with a fan, but when I attach my SSD drive via a SATA-to-USB3.0 converter I had serious stability issues. When I connected the drive via a powered USB hub these problems were solved.

I agree with tjamaa. What are your temps when trying to use the HDD? Your device will experience all kinds of issues without some kind of minimum spec of passive cooling via e.g. a heatsink…

I do have an heat sink but its not enough.
I ordered a new case with a fan. I hope it will fix it.

A fan will absolutely fix it. My temps went from well over 66C to under even 36C with a fan and heatsink combo. But I got a very good fan. A 5V Noctua.