@stanwood Thank you very much, it worked fine on my nexus5
@AppLee Thank you for your message, I did not tried your suggestion as my issue was already solved.

To be able to write once on read-only filesystem

sudo mount -o rw,remount /

But as said, the rootfs is mounted read only for good reasons.

@arubislander
Thank you for your interest, I think the SD card is seen as by the file manager as 2667-CBA1 but with several empty directories.... automatically created ?

I inserted a 30 Go SD card fat32 formatted in a FP2.
At every reboot, the same message occurs : "Storage device detected. This device will be scanned for new content"
I would like to use the SD card to store pictures, music or other personal data, but I do not know how to mount it.
Thanks for your help

@stanwood Thank you very much, it worked fine on my nexus5
@AppLee Thank you for your message, I did not tried your suggestion as my issue was already solved.

@stanwood It looks good, but after
sudo apt install anbox-ubuntu-touch android-tools-adb

the terminal indicates "no enough free space in /var/cache/apt/archives/
I do not how to resolve this issue

To be able to write once on read-only filesystem

sudo mount -o rw,remount /

But as said, the rootfs is mounted read only for good reasons.

May be it is only the antenna like explained here:
https://gabgagnon.ca/comment-regler-le-probleme-de-gps-du-nexus-5/