Partitions About

Partition 5 (rootfs B Alternate rootfs, for use by automatic upgrades) Why can’t we use this partition? When I want to start Fydeos from this partition it gets stuck on black screen

It’s detailed here:
https://chromium.googlesource.com/chromiumos/docs/+/HEAD/disk_format.md

rootfs B Alternate rootfs, for use by automatic upgrades.

This is exactly what I’m asking. Why can’t we use this part? When I mount rootfs B, I see that the system is loaded in it, but fyde os does not start from this partition.

problem solved…
I had to manually type the PARTUUID number I set with sudo blkid into the grub.cfg file in the efi partition.
Now I can do updates without deleting data