External HDD doesn't show up in /dev on raspberry pi

Question

here's my problem: I have an old 500GB HDD drive from one of my old laptops which I connected to my Pi via USB. First issue: Every time I plug in the device, the Pi reboots. I already read this is due to some issue with the power supply and it's not really bothering me since I inteded to leave the HDD connected to the Pi anyways. BUT

Second issue: The HDD refuses to show up in /dev, therefore I can't mount it! It works perfectly fine on my desktop PC (where I also formatted it with ext4) but it won't work at all on the Pi.

Maybe those to issues are somehow connected to each other?! Help very welcome...

Filesystems on the pi are:

 Device Boot      Start         End      Blocks   Id  System
/dev/mmcblk0p1            4096      147455       71680    c  W95 FAT32 (LBA)
/dev/mmcblk0p2          151552    31504383    15676416   83  Linux

output of lsusb is

Bus 001 Device 002: ID 0424:9512 Standard Microsystems Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp.

output of lsblk is

NAME        MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
zram0       254:0    0  10M  0 disk 
mmcblk0     179:0    0  15G  0 disk 
|-mmcblk0p1 179:1    0  70M  0 part /boot
`-mmcblk0p2 179:2    0  15G  0 part /

Formatting the external HDD with FAT32 doesn't work either

Thanks!

Solution 1

Possible reasons why a USB hard drive doesn't show up in /dev when connected:

• Drivers for your USB chipset or hardware not loaded or not working properly (try updating kernel if possible)
• USB driver had a problem initializing the device - typically wrong driver, defective or unsupported hardware
• Some hardware may act bad if too much power is consumed by attached USB devices
• Hard drive is dead, defective or not communicating with the SATA/IDE to USB bridge (hard drive not connected to enclosure properly?) - SATA/IDE to USB bridge may also be dead or defective.
• Hard drive is not powered on or not getting enough power
• Physical issue with USB cable or port

Try putting the hard drive in an enclosure that is separately powered and see if you have better luck with that.

Solution 2

You are right 400ma is not enough for Raspberry to feed the external drive. I had a similar problem and solved it by attaching a powered USB hub, and voila!! disk recognized and mounted.

Comments

[Ramhound]

Lets start with the basics. What filesystem are we talking about? In addition what sort of partition are we talking about ( MBR or GPT )?

[terdon]

What makes you think it is not detected? Could you post the output of lsusb and lsblk?

[Ƭᴇcʜιᴇ007]

Does the HDD work when you plug into another device via USB (like a PC)?

[terdon]

@techie007 yes, the OP mentions it works on his desktop PC.

[terdon]

Please don't post info in the comments, edit your question instead.

[Ƭᴇcʜιᴇ007]

@tedron So he does. me = duh...

[Ramhound]

@FabianNick - Use an actual computer and the tool of your choice. Update your question with that information. I skipped over or glazed over the ext4 filesystem my aplogizes.

[terdon]

I expect the disk is visible from the pi. Please post the output of the two commands I asked for, they will tell us if you can see the drive.

[Ramhound]

Sounds like this is either a FAT32 compatability problem with the OS you have installed or connected to the fact the Raspberry PI reboot when the drive is connected. I would resolve the second issue before looking into using something other then FAT32.

[fpnick]

@Ramhound I formatted the external HDD with FAT32, but nothing changed...

[Alvin Wong]

If the hdd is directly powered by USB, forget about filesystem format. The RaspberryPi cannot really output enough power to spin up the hdd, probably causes a voltage drop when plugged in thus the reboot. The hdd may not get enough power to keep itself in normal operation, so the USB device won't even let the host detect it.

[fpnick]

@AlvinWong Yes it is... Maybe getting an externally powered USB hub would help?! BTW: I used an USB-Y-chord and attached the HDD to BOTH USB ports, but that didn't work either...

[FSMaxB]

I can't really figure out if you tried this, but what about a powered USB-Hub if the Y-chord doesn't work. And you could take a look at the udev events when plugging in the drive, don't know how to do this, though. Maybe "tail -f /var/log/kernel.log" while plugging in and out?

[fpnick]

checking the events doesn't work, since the Pi shuts down when I plug the hdd in... And I cannot try the powered USB-Hub since I don't own one, but I think I will get one just...

[fpnick]

Will get an externally powered USB hub...

[fpnick]

The HUB arrived today and it works perfectly fine now. Thanks!