I run OpenWRT on my x86 PC(Lenovo tiny series, UEFI+amd64), use the latest 21.02 stable version, squashfs+efi, and burn into USB drive via Rufus, all new flash, no upgrade, no restore backup configuration.
I totally follow [[https://openwrt.org/docs/guide-user/additional-software/extroot_configuration|this guide]] to configure extroot, of course enablemodified the partition /dev/sda1 and something like that. But after reboot I found Extroot partition don't mount automatic as expected.
Try some times still not work I found not checked enable on luci,so I add option enabled '1' in /etc/config/fstab, but still don't work property. I also follow troublshooting on that article increase delay_root, not work, but true, mount it without problems from a shell after boot.
logread | sed -n -e "/- preinit -/,/- init -/p"
Full logs at [[https://pastebin.com/etrRj6Bt|here]] , list relative part below
user.info kernel: [ 7.764620] block: attempting to load /etc/config/fstab
user.err kernel: [ 7.768095] block: unable to load configuration (fstab: Entry not found)
user.err kernel: [ 7.769569] block: no usable configuration