Adding external HDD to Raspberry Pi

[Guy Sheffer]

I've got one of these.
Among other things it lets me power an external hdd.
http://www.cnx-software.com/2013/12/21/x100-raspberry-pi-expansion-board-adds-vga-output-rtc-and-more/

Alternatively make sure when you get a powered hub it does not backfeed in
to the pi. You might need to disconnect pin +5V on the usb cable between
the pi and the powered usb hub.

Guy
On Dec 15, 2014 1:37 AM, "E.S. Rosenberg" <esr+linux-il at g.jct.ac.il> wrote:

> 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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>>> Linux-il at cs.huji.ac.il
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>>>
>>>
>>
>> --
>> <http://au.linkedin.com/in/gliderflyer>
>>
>
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