Write activity on filesystem by system components


#1

Hi!

We are currently considering using BalenaOS for our Raspberry Pi based product. One of the issues we have seen with our homebrew solution has to do with filesystem-corruption during power-loss.

Thus I was pleased to see that BalenOS comes with read-only root as default:
https://www.balena.io/docs/reference/OS/overview/2.x/#stateless-and-read-only-rootfs

While this is great, the documentation does not mention when there is activity on the read-write parts of the filesystem.

Can I control when the system writes to these parts? Is there any way to make the system completely read-only?

Thanks!


#2

Hey @arnt,

balenaOS is generally more resilient to power-loss, by far the most writes are during pulling an application update for which balenaEngine also ensures atomicity. so the only write we can’t guarantee won’t cause corruption are user application writes.

The advantage is that even if the data partition, which has the main I/O load, gets corrupted you can always rescue the device as the main services, like VPN and networking, will still be up and running.

Resuming, you will be better off with balenaOS than most operating systems for the RPi.

Hope it answers your question,
Cheers