USB Harddisk without power supply unit

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I consider to use a banana pi for backup purposes. I have a 1000 gb USB 2.5 " harddisk without power supply. Can I rely that the Banana Pi provides enough power for the harddisk to work safely?

Thank you for answer.

I have 1T USB 3 2.5'' hard disk too and on high cpu load Banana Pi shutdown
I use 5V/2A power supply so...

I consider to use a banana pi for backup purposes. I have a 1000 gb USB 2.5 " harddisk without p ...
fergru Posted at 2014-8-23 11:08

   a) Banana Pi doesn't give extra power for HDD. You must supplied enought power from power supply      b) on Banana Pi board is coil for filtering power supply for HDD. unfortunately it has resistance, and not all disk starting with this power source...

Post Last Edited by daristan at 2014-8-24 05:05

I use 1tb usb3 hard drive with it, during idle the total power use is less than 5w, however you need to make sure  the power adaptor and usb cable can achieve up to 9 to 10w. I run samba with ext4 on lubuntu os,  no problem to transfer many GB of data or videos at 20mb/s on lan, run owncloud, download torrents without problem. If your power is not sufficient it will auto poweroff. All this are done in transmission only on 24/7. My advice is get a good power supply, don't forget usb cable also play a big role, different cable deliver different watts. I only discover this lately and different cable can be 5 watts different from same adaptor.

Post Last Edited by actkk2000 at 2014-8-24 17:01

It would be better a Sata disk, but if you have not, then a USB hub with external power is needed.
In that case you will need to cut 5V red wire from inside to avoid any voltage feedbacks.
This is the how to:
http://www.thebitbangtheory.com/ ... to-a-cheap-usb-hub/
http://pihub.blogspot.ca/2012/06 ... ly-and-powered.html

Edited by elatllat at 2014-10-18 04:19
daristan replied at 2014-8-24 05:00 ....20mb/s...

That seems a bot slow..
USB2 is 280 Mbit/s (35 MB/s)
The raspberrypi gets 30MB/s
Can someone post the output of a usb dd test on the bananapi?

elatllat replied at 2014-10-18 04:06
That seems a bot slow..
USB2 is 280 Mbit/s (35 MB/s)
The raspberrypi gets 30MB/s

He spoke about LAN throughput. We had a thread regarding tuning network throughput so that it can match USB speeds (which works but is IMHO insane because using USB storage on a board with a SATA connector is always a bad idea)


BTW: Most people using dd for 'benchmarking' do it wrong (file size too small, not deactivating FS cache/buffers -- iflag/oflag direct -- and therefore measuring Linux filesystem cache implementation but not the storage)

Edited by silentcreek at 2014-10-18 15:09

I tested 3 different 2.5" USB harddrives with my headless Banana Pi server setup and my experience is this:

I have two Toshiba and one Western Digital drive that I tried on the Banana Pi. Unfortunately, my Western Digital drive does not work reliably without an additional powered USB hub. It's a WD Elements 750GB USB3.0 harddrive. Sometimes the BPi will power up with it plugged in, but a lot of times it just won't (I'm using a 5V/2A power supply as recommended). And even if it does power up, after a longer period I saw errors with the USB connection being reset. My guess is, that this particular drive is a 7200rpm drive which needs more power to spin up (I suspect so, because it's also significantly louder than all of my other 2.5" drives).
The two Toshiba drives I tested are a Toshiba Stor.e Basics 1TB 2.5" USB3.0 and a Toshiba Stor.e Slim for Mac 500GB 2.5" USB3.0. They both work absolutely fine without additional power supply. Two harddrives at the same time don't work for me, but one harddrive and one extra USB flash drive work.

My conclusion:
1.) You have to make your own tests to be sure, if your specific drive works without additional power supply. Not all drives work.
2.) If you want to use two external USB hard drives, you will need a seperate power supply (e.g. powered hub).
3.) If you are planning to buy a new harddrive for your BPi, I'd grab an internal 2.5" drive instead of a USB drive. But if you want two use drives you already own (like me), just give it a try.



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