It seems that the RPi foundation has issued a beta version of the USB bootloader (which does not require a microSD card in addition). I presume I could install Astroberry onto my USB SSD after setting the SSD up as the (only) boot device. But is there a way of using the Astroberry 2.0.1 image file directly?
So I now have Astroberry 2.0.1 running on my RPi4 directly from a Sandisk Extreme SSD. I followed a couple of videos on Youtube ( and ). Once I had Raspbian Buster running from the SSD with no microSD card, then using Balena Etcher, I burned the Astroberry 2.0.1 image to my SSD. I copied into the boot partition the 14 .elf and .dat files which are on the GitHub repository (as described in the second YouTube video, and as I had already found successful with the plain Raspbian) . So Astroberry now boots at lightening speed from the SSD. Only one small problem yet to solve - I need to expand the file system to occupy the whole of the SSD. At present I have access only to around 8GB of the much larger SSD. I tried using raspi-config Menu item 7 Advanced Options Menu item A1 Expand Filesystem but get the message "sda2 is not an SD card. Don't know how to expand".
I guess I need to seek some help from the experts on the RPi forum!
Yes - you can boot directly from ‘any’ USB storage device. My Astroberry implementation now resides on a Sandisk Extreme SSD which is super fast. I have also tried out a 1TB 2.5” hard drive in an IcyBox USB3 carrier. It works pretty well although RPi agnostics tests gives an overall FAIL due to random read /write speed being a little below the test threshold score.
Ok, great to know. Now the next question; is that really a smart thing to do!? I bought the extreme for the purpose of downloading images from the camera to it rather than the SD card. I have it plugged into a Ankor USB 3.0 powered hub along with most of the equipment and I have had no issues with that arrangement. Other than I have to run a symlink command to link that drive to a 'nice' name in the system. I tried adding a command to the 'fstab' file (and the rules file), but the system hung; I think because it tried booting before that drive was recognized (mounted). Anyway that is not a big deal. I guess I am worried about mixing operating system and data on the same 'big' drive (not that we don't do that all the time, but if it goes for some reason you loose both!) There is a second USB 3.0 port on the Rpi 4, would it make more sense to use that with a smaller flash drive for the Astroberry Server System and keep the large one just for data (it makes it easy to transfer images to my PC where I process the data)?
And now the real question is if I do have a flash drive as the boot device can I also use some of that memory for a 'swap' file?
My experience is that SD card is less reliable that SSD drive, when used as a main system drive. So I believe running from SSD is not only faster but also more reliable.
This also applies to swap partition. You can set a dedicated partition and use it as swap. You would need to add it to /etc/fstab so system uses it at boot time.
The amount of memory is not that important if you're not going to save large fails at it, speed is more important. If you will need to save files at some points, you could just use an external HDD, and it will be okay. Just try to not mess up anything, and there should not be any problems. Even if something happens, don't panic because the files can be recovered. You can always contact DATA RECOVERY SERVICES
, they know how to recover all the lost or deletes files from your computer.