I think we need to compile a kernel with CONFIG_OVERLAY_FS=m and CONFIG_KERNEL_XZ=y, perhaps also CONFIG_KERNEL_LZ4=y for fast oprion. Perhpas I'm wrong, not so expert in that and, until now, never tried to compile the kernel, a must to do in the life, so I'm just a novice. At the momnt I put in eggs info two commands 'zgrep CONFIGKERNEL /boot/config-$(uname -r)' and 'zgrep CONFIG_OVERLAY_FS /boot/config-$(uname -r)' to check the presence
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