Impossible to install in SteamOS - No free space in partition

[goyetus]

While trying to install in Steam Os (AMD 5900x + 9070xt) :

SteamOS is fresh installed. Seems like SteamOS dont have the same empty space as steam deck ?
Error due to "No space" in the main partition.
Your install , throw error due to "no space" in patition.

LOG:

: Proceed with installation? [Y/n]

(7/7) checking keys in keyring [###########################################################] 100%

(7/7) checking package integrity [###########################################################] 100%

(7/7) loading package files [###########################################################] 100%

(7/7) checking for file conflicts [###########################################################] 100%

(7/7) checking available disk space [###########################################################] 100%

error: Partition / too full: 5121 blocks needed, 0 blocks free
error: not enough free disk space
error: failed to commit transaction (not enough free disk space)
Errors occurred, no packages were upgraded.

[goyetus]

you should use "sudo steamos-readonly disable" before installing?

(please, update instructions for linux newbies......)

Thanks !!!!

Edit:
I checked the Install.sh and you do a readonly disable , so, it´s not the problem.....