i remembered I had to flash vanilla first to get parttions aligned with vanilla openwrt so did a
uboot flash of gl-ar750s-3.0-1011_clean.img.
this casues same problem of having luci blank unset password login failure.
here is my block info
root@OpenWrt:~# block info
/dev/mtdblock0: UUID=“xxxxxx56xx” VERSION=“1” TYPE=“ubi”
/dev/mtdblock6: UUID=“00794cfc-1a8d9629-07b5039a-xxxxxxx” VERSION=“4.0” MOUNT=“/rom” TYPE=“squashfs”
/dev/mtdblock7: MOUNT=“/overlay” TYPE=“jffs2”