cspan wrote: ↑
Sat Mar 24, 2018 3:28 pm
With respect to USB boot (I'm mainly interested in the 3B+ at this point), there seem to be a number of possible ways to do it:
- flash/thumb drive
- external hard drive powered via USB (e.g., Seagate Slim, WD My Passport)
- external hard drive with its own power supply (e.g., via a powered USB hub, its own power supply/wall wart, or even an internal hard drive set into a powered SATA dock
Which of these would be most suitable for use of the Pi as a desktop replacement (email, Libreoffice, browsing, some basic picture editing but no video editing)?
Most inexpensive USB flash drives will be slow as an OS drive. They just aren't designed for the kind of I/O needed for OS use. SD cards have the same problem, but there are new "A1" class SD cards designed for faster random I/O and those work much better.
An SSD works surprisingly well, in spite of USB 2.0 port limits. There are many performance enhancing features on an SSD that cheap flash drives and SD cards don't have, which not only makes them faster, it also makes them more robust devices in terms of reliability and data integrity.
External hard drives powered by the Pi's USB ports may have trouble spinning up fast enough to be detected as a boot device before the boot loader times out. Some will work, but not all. There are quite a few here booting their Pi3 computers from USB powered hard drives, so it does work for some. The only way to know if it will work for you is to give it a try.
External hard drives with their own power, that are powered up before the Pi is booted, will usually work great.
Do note that the boot loader in the Raspberry Pi is rather simple, due to limited space for the code in the SoC, so there are some devices that are incompatible and simply won't work. This situation is supposed to have been improved with the new 3B+ and there should be fewer incompatible devices with that model.
Keeping the boot partition on an SD card and running the root OS from a USB device was the old-school way of doing things before USB boot was introduced with the Pi3B model. If you have one of the unlucky incompatible devices, you can often get it working by keeping /boot on SD. The /boot partition is treated as read-only except for firmware/kernel updates, so an SD card used in this manner is subject to very little wear.
So my recommendations are...
1. For simplicity with good performance, boot from one of the new "A1" class SD cards.
2. For the best overall performance, boot from a USB SSD drive.
3. If you need loads of storage, or need to record large amounts of data, go with a hard drive (preferably self-powered).
There's also no reason you cannot combine devices, like boot from an A1 SD card and use a hard drive for storage.
tanghao wrote: ↑
Thu Mar 08, 2018 7:09 am
Woah. That is the most awesome thing ive seen all day. Would this work with a pi 2
If you have the newer Pi2B v1.2 you might be able to follow the procedure for the Pi3B and boot from USB. They use the same SoC, so in theory it should work, but I don't have one so I can't confirm it.
You can USB boot the older Pi1B+ and Pi2Bv1.1 by writing the latest Raspbian image to the USB drive directly (preferably using Etcher) and then copying just the bootcode.bin file from the USB drive's boot partition to a FAT32 formatted SD card. The Pi will execute bootcode.bin from the SD card, and that will boot the USB device. You must only have a single USB storage device connected for this to work reliably, because bootcode.bin will only attempt to boot the first USB drive it finds, and there is no way to guarantee that will be your intended boot device with multiple drives connected. This also works for the Pi3B, but not the new 3B+ model.
My mind is like a browser. 27 tabs are open, 9 aren't responding,
lots of pop-ups...and where is that annoying music coming from?