[PROBLEM] Failed to isolate default target

[Xetar]

Hello,


In August of this year I tried Moode with my Raspberry Pi 3a, and I absolutely love the system. It took me some time to get used to it and to properly setup the raspberry, but I got it to run for quite some time and splendidly.


However suddenly I'm experiencing that the raspberry Pi won't boot anymore. I suspect it has something to do with how I boot/shutdown the raspberry pi: The entire audio system (including the raspberry) is switched on-off with a 230-volt switch. Switched on usually in the morning/afternoon, and switched-off before going to bed. I fear this may have corrupted the SD card. This is the error code that I'm getting, as shown in the attachment: 'failed to isolate default target'

(Apologies for the bad picture quality, it was taken off a one-time beamer projection on a wall since I'm running the raspberry pi without peripherals)

Is there anything I can check/repair following this error?

I'm running Moode 6.7.1 on a raspberry Pi 3A.

   

[TheOldPresbyope]

This error is pretty obscure. For the most part your start up messages seem ok. In particular, the kernel was able to mount the root filesystem located in the second partition of your uSD card. This to me means the basic layout of the uSD card is still ok. However, systemd seems to be getting into a target-defining file that my normally booting moOde player on an RPi3A+ doesn't. I think this is the cause of the "Failed to isolate default target" message.

I think the conservative thing to do is assume the filesystem is corrupt and flash a new one. Are you using a quality name-brand class 10 (or above) uSD card? If not, I suggest you use one. I've had good luck with brands such as SanDisk Ultra, Hitachi, and Samsung.

The conventional wisdom is to always shutdown the OS on an RPi before killing the power. For moOde this means using the m>power>shutdown "button" or invoking an appropriate script from the command line or using a real button and gpio-based solution.

Having said that, Tim has reported that he's killed power on his systems without ill effect and certainly I have too (sometimes without meaning to!). We're probably playing with fate but recent RPi models don't seem to suffer the problems experienced with the early generation models.

Regards,
Kent

[DRONE7]

A very simple on/off button that you can make and it switches the Pi safely.
https://howchoo.com/g/mwnlytk3zmm/how-to...spberry-pi

(Even though the instruction is for a Pi4 I've used it for other Pi with no problems.)

[Xetar]

Do you expect that the filesystem has become corrupt due to write actions that were interrupted due to me killing the power? In my expectation the raspberry pi can function in a read-only mode, as the only thing it has to do is boot up and read the music files. Perhaps it'll write a few logs, but there wouldn't be a real need to do so either.

Would it prevent any such issues as the above if the system were purely read-only or can corruption of the file system even happen when no write actions are being done?

Anyhow, I'll probably make a clean install of the system and give it a new try. Perhaps with a different uSD card.

[TheOldPresbyope]

Yes, it is possible for mass storage to become corrupt if the OS is killed during a write operation. The software shutdown/poweroff/halt commands are intended to ensure it's done cleanly.

No, moOdeOS is not a read-only system. It would take some architectural changes to make it almost so. Even if it ran solely in-memory there would be times when it has to save to its storage medium otherwise a user couldn't save configuration settings, update the library, and such. 

As well, sometimes weird things happen when multiple pieces of equipment are interconnected and powered off or on "simultaneously."

I can think of ways of dealing with this but the simplest still seems to be to use one of the commercial or DIY solutions for shutting down an RPi. This could be coupled with a power sequencer for your audio stack.

Regards,
Kent