Adding external HDD to Raspberry Pi

[E.S. Rosenberg]

Raspberry Pi uses USB2.0, it can't provide enough current to big peripheral
devices full stop.
It's so bad that plugging in a disk-on-key while it's running can cause a
sufficient voltage drop to reboot the system (after which the d-o-k will
work).
That's why you need to have a powered USB hub, USB3.0 allows more power to
flow through the ports so it will be more efficient with ports (with USB2.0
external HDDs of the 3,5" variety tend to have a second USB connector to
get extra current).

HTH,
Eliyahu - אליהו

2014-12-14 22:41 GMT+02:00 Amos Shapira <amos.shapira at gmail.com>:
>
> Get a powered USB hub (i.e. a usb hub which also connects to a wall power
> socket). I'm not familiar with RPi USB version but check for USB 3.0 vs.
> 2.0.
>
> On 15 December 2014 at 06:07, Gabor Szabo <gabor at szabgab.com> wrote:
>
>> Hmm, good question. The Raspberry does see the device when it is
>> connected, so is it possible that it needs more
>> power after later on?
>>
>> How can I check?
>>
>> If the problem is lack of current, how can I solve that? Can I put one of
>> these usb hubs that also provide power between the two?
>>
>> Gabor
>>
>> On Sun, Dec 14, 2014 at 8:43 PM, E.S. Rosenberg <esr+linux-il at g.jct.ac.il
>> > wrote:
>>>
>>> Are you providing the external HDD with sufficient electricity? The
>>> Raspberry is most likely not capable of providing enough current...
>>>
>>> 2014-12-14 19:30 GMT+02:00 Gabor Szabo <gabor at szabgab.com>:
>>>
>>>> So finally I install the Raspberry Pi I bought a few weeks ago and
>>>> wanted to add an external HDD.
>>>> I plugged in the external hard drive and /var/log/syslog printed the
>>>> following:
>>>>
>>>>
>>>> Dec 14 17:02:55 pi kernel: [  759.981949] usb 1-1.3: new high-speed USB
>>>> device number 8 using dwc_otg
>>>>
>>>> Dec 14 17:02:55 pi kernel: [  760.163364] usb 1-1.3: New USB device
>>>> found, idVendor=1058, idProduct=0820
>>>>
>>>> Dec 14 17:02:55 pi kernel: [  760.163398] usb 1-1.3: New USB device
>>>> strings: Mfr=1, Product=2, SerialNumber=5
>>>>
>>>> Dec 14 17:02:55 pi kernel: [  760.163414] usb 1-1.3: Product: My
>>>> Passport 0820
>>>>
>>>> Dec 14 17:02:55 pi kernel: [  760.163429] usb 1-1.3: Manufacturer:
>>>> Western Digital
>>>>
>>>> Dec 14 17:02:55 pi kernel: [  760.163444] usb 1-1.3: SerialNumber:
>>>> 57583431413432454363833
>>>>
>>>> Dec 14 17:02:55 pi kernel: [  760.169522] usb-storage 1-1.3:1.0: USB
>>>> Mass Storage device detected
>>>>
>>>> Dec 14 17:02:55 pi kernel: [  760.181935] scsi0 : usb-storage 1-1.3:1.0
>>>>
>>>> Dec 14 17:02:56 pi kernel: [  761.183065] scsi 0:0:0:0: Direct-Access
>>>>   WD       My Passport 0820 1012 PQ: 0 ANSI: 6
>>>>
>>>> Dec 14 17:02:56 pi kernel: [  761.187365] scsi 0:0:0:1: Enclosure
>>>>   WD       SES Device       1012 PQ: 0 ANSI: 6
>>>>
>>>> Dec 14 17:02:56 pi kernel: [  761.189473] sd 0:0:0:0: [sda] Spinning up
>>>> disk...
>>>>
>>>> Dec 14 17:02:56 pi kernel: [  761.277106] sd 0:0:0:0: Attached scsi
>>>> generic sg0 type 0
>>>>
>>>> Dec 14 17:02:56 pi kernel: [  761.278094] scsi 0:0:0:1: Attached scsi
>>>> generic sg1 type 13
>>>>
>>>>
>>>> But then when I try to run
>>>>
>>>>
>>>> $ sudo fdisk /dev/sda
>>>>
>>>> I get
>>>>
>>>> fdisk: unable to open /dev/sda: No such device or address
>>>>
>>>> $ ls -l /dev/sda
>>>>
>>>> brw-rw---T 1 root floppy 8, 0 Dec 14 17:21 /dev/sda
>>>>
>>>> $ sudo fdisk -l
>>>>
>>>> only lists the sdcard
>>>>
>>>>
>>>> The external disk is brand new and it has NTFS on it. I have not
>>>> handled disk in linux for a long time, but a I recall I am supposed to use
>>>> fdisk to partition it and then use mkfs.ext4 to format.
>>>>
>>>>
>>>> So what am I missing here?
>>>>
>>>>
>>>> Gabor
>>>>
>>>>
>>>>
>>
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>
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> <http://au.linkedin.com/in/gliderflyer>
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