Booting a Raspberry-Pi 3B without using a SD-Card
Hi, If you have a Raspberry Pi Model 3B, then you may be able use it with no micro SD-Card and have it boot Raspbian off a USB flash drive stick. I have found this possible with an Apacer AH356 64GB USB 3.1 Flash Drive<https://www.pbtech.co.nz/product/MEMAPC11464/Apacer-AH356-64GB-USB-31-Flash-Drive--Backwards-co> stick that I bought from PB-Tech a couple of weeks ago for $21.85. Admittedly you can buy a micro SD-card like the Apacer 64GB microSDXC UHS-I Class10<https://www.pbtech.co.nz/product/MEMAPC81064/Apacer-64GB-microSDXC-UHS-I-Class10-w-1-Adapter-RP> from PB-Tech for $28.75 and put Raspbian onto it. So using the USB flash drive stick only saves a few dollars. However, there may be other advantages over using a USB flash drive vs. a micro SD-Card for the Raspbian OS. For example, you can shutdown the Raspberry Pi and remove the USB stick, take it to another computer, and backup your data. I also installed the Raspbian distro onto WD Elements Portable 2TB 2.5" USB 3.0 External HDD<https://www.pbtech.co.nz/product/HDDWDX2621/WD-Elements-Portable-2TB-25-USB-30-External-HDD> which PB-Tech sell for $129. The R-Pi (with no SD-Card) would not boot this drive. Possibly because the USB drive is too slow to initialize after power on??? I also found that the R-Pi would not boot up Raspbian on an old 8GB Kingston USB flash drive. Maybe its too slow to initialize??? All the above tests were done using the current latest Raspbian release which is dated 2018_10_09. FYI: Below are details on how to install the Raspbian distro image onto a USB flash drive stick. cheers, Ian. Installing the Raspbian distro onto USB flash drive... Download the latest 1.4GB Raspbian distribution file: 2018-10-09-raspbian-stretch.zip Unzip the file to create a 4.1GB image file: 2018-10-09-raspbian-stretch.img Copy the 4.1GB image to a USB flash drive stick... $ sudo dd bs=4M if=2018-10-09-raspbian-stretch.img of=/dev/sdX status=progress conv=fsync Note: For the device /dev/sdX replace the X with the drive letter of your USB flash drive stick. e.g. /dev/sdc Insert the USB flash drive stick into the R-Pi model 3B. Remove any SD-Card that may be installed in the Raspberry Pi. Power on the R-Pi. After about 10 seconds the colourful POST display will appear, and the USB stick will commence its first boot. It will detect that it is a 4.1GB partition, expand to being a partition that fills the whole of the USB flash drive stick and reboot. The second reboot will be slow and takes about one minute. I assume it is expanding the squashed file system??? Subsequent reboots are faster.
Admittedly you can buy a micro SD-card like the Apacer ...
Don’t buy Apacer. The ones I got had rubbish write rates.
I agree. Kingston ones are quite snappy. Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/
Admittedly you can buy a micro SD-card like the Apacer ...
Don’t buy Apacer. The ones I got had rubbish write rates.
I agree. Kingston ones are quite snappy.
...fair comment on the performance of micro SD-cards, but the main point of my R-Pi model 3B testing is that you do not need to buy a micro SD-card at all and the equivalent capacity USB flash drives are cheaper. I was attempting to do an apples to apples price comparison: Apacer 64GB micro SD-card $28 Apacer 64GB USB flash drive $21.85 A secondary point is that not all USB flash drives with Raspbian installed will boot with no mirco SD-card. I've now tested 2 that will boot: Apacer AH356 64GB USB 3.1 Flash Drive $21.85 SanDisk Cruzer Switch 64GB USB Flash Drive $21.85 (going EOL) Gordon Hollingworth wrote a blog<https://www.raspberrypi.org/blog/pi-3-booting-part-i-usb-mass-storage-boot/> in August 2016 in which he states his reasons why some USB flash drives won't boot a R-Pi 3B with no micro SD-card... <https://www.raspberrypi.org/blog/pi-3-booting-part-i-usb-mass-storage-boot/> There are a couple of known issues: Some flash drives power up too slowly. There are many spinning disk drives that don’t respond within the allotted two seconds. It’s possible to extend this timeout to five seconds, but there are devices that fail to respond within this period as well, such as the Verbatim PinStripe 64GB. Some flash drives have a very specific protocol requirement that we don’t handle; as a result of this, we can’t talk to these drives correctly. An example of such a drive would be the Kingston Data Traveller 100 G3 32G. His blog states that these USB drives would boot-up rasbpian OK... Sandisk Cruzer Fit 16GB Sandisk Cruzer Blade 16Gb Samsung 32GB USB 3.0 drive MeCo 16GB USB 3.0
From looking through PB-Tech's range of 64GB USB flash drives, there are about 30 different drives, from 9 different vendors and the price ranges from $21 to $71.
At this stage I can only confirm that 2 of these 30 will boot raspbian on my R-Pi 3B when I have no micro SD-Card. If you buy another brand / model of USB flash drive and your R-Pi model 3B will boot raspbian OK, then please let everyone know. cheers, Ian. PS: When it comes to micro SD-Cards from PB Tech, then there are about 20 in the 64GB capacity and they are priced from the Apacer at $28 to a SanDisk at $102. For write performance then it seems the best on offer is: SanDisk 64GB Mobile Extreme Pro microSDXC 95MB/S read, 90MB/s write CLASS 10/UHS-3 at $102.
On Fri, 2 Nov 2018 00:07:10 +0000, Ian Stewart wrote:
...fair comment on the performance of micro SD-cards, but the main point of my R-Pi model 3B testing is that you do not need to buy a micro SD-card at all and the equivalent capacity USB flash drives are cheaper.
I should point out my poor experience was with Apacer USB drives, not SD cards. But I suspect the quality issues would not be too different.
I should point out my poor experience was with Apacer USB drives, not SD cards.
Using my old laptop with USB2 ports I get 17MB/s write speed when writing a 4.1GB image to the Apacer AH356 64GB USB 3.1 Flash Drive stick... $ sudo dd bs=4M if=2018-10-09-raspbian-stretch.img of=/dev/sdb status=progress conv=fsync [sudo] password for ian: 4127195136 bytes (4.1 GB, 3.8 GiB) copied, 239 s, 17.2 MB/s 986+0 records in 986+0 records out 4135583744 bytes (4.1 GB, 3.9 GiB) copied, 241.279 s, 17.1 MB/s Possibly it would write faster if I had USB 3 ports on my laptop. If one goes to the Apacer<https://consumer.apacer.com/eng/content.php?sn=951> website, then their "specification" about their AH356 USB stick is... Transmission at USB 3.1 Gen 1 SuperSpeed Equipped with USB 3.1 Gen 1 interface featuring a 5Gbps bandwidth, AH356 operates at a superlative speed, allowing remarkable read/write speed, making file exchanges between PC and laptop easier than ever. I'm not sure exactly how fast a "remarkable read/write speed" is in MB/s ;-)
On Fri, 2 Nov 2018 05:43:18 +0000, Ian Stewart wrote:
Using my old laptop with USB2 ports I get 17MB/s write speed when writing a 4.1GB image to the Apacer AH356 64GB USB 3.1 Flash Drive stick...
If that’s a steady rate, then that sounds a lot better than the 32GB Apacer sticks I bought. They would fluctuate erratically, from a few megabytes per second down to maybe a few hundred kilobytes per second. The other brand I bought (I think it was Sandisk) was much more consistent.
participants (3)
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Ian Stewart -
Lawrence D'Oliveiro -
Peter Reutemann