I used to change the root=PARTUUID= setting in cmdline.txt of the (micro) sd-card of RPI 1B and 2B models to the PARTUUID of the USB-disk. Then the RPI will run with root on the SDA parttion.
When raspbian buster (or the latest version of stretch) is written with balenaEtcher, both sd-card and usb-disk get the same PARTUUID. See below. blkid /dev/mmcblk0p1: LABEL_FATBOOT="boot" LABEL="boot" UUID="4BBD-D3E7" TYPE="vfat" PARTUUID="738a4d67-01" /dev/mmcblk0p2: LABEL="rootfs" UUID="45e99191-771b-4e12-a526-0779148892cb" TYPE="ext4" PARTUUID="738a4d67-02" /dev/sda1: LABEL_FATBOOT="boot" LABEL="boot" UUID="4BBD-D3E7" TYPE="vfat" PARTUUID="738a4d67-01" /dev/sda2: LABEL="rootfs" UUID="45e99191-771b-4e12-a526-0779148892cb" TYPE="ext4" PARTUUID="738a4d67-02" /dev/mmcblk0: PTUUID="738a4d67" PTTYPE="dos" With the set-ptuuid script downloaded from:https://www.raspberrypi.org/forums/viewtopic.php?t=253562 we can change the PARTUUID of the USB-disk (or the sd-card). The script also changes the PARTUUID settings in cmdline.txt and other files. Example ===== Boot from the sd-card with the usb-disk connected Now change the PTUUID of the USB-disk ./set-ptuuid /dev/sda random Set PTUUID on /dev/sda to e4f3c2c9 (y/n)? PTUUID on /dev/sda is set to e4f3c2c9 blkid /dev/mmcblk0p1: LABEL_FATBOOT="boot" LABEL="boot" UUID="4BBD-D3E7" TYPE="vfat" PARTUUID="738a4d67-01" /dev/mmcblk0p2: LABEL="rootfs" UUID="45e99191-771b-4e12-a526-0779148892cb" TYPE="ext4" PARTUUID="738a4d67-02" /dev/sda1: LABEL_FATBOOT="boot" LABEL="boot" UUID="4BBD-D3E7" TYPE="vfat" PARTUUID="e4f3c2c9-01" /dev/sda2: LABEL="rootfs" UUID="45e99191-771b-4e12-a526-0779148892cb" TYPE="ext4" PARTUUID="e4f3c2c9-02" /dev/mmcblk0: PTUUID="738a4d67" PTTYPE="dos" cat cmdline.txt console=serial0,115200 console=tty1 root=PARTUUID=e4f3c2c9-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait quiet init=/usr/lib/raspi-config/init_resize.sh Now reboot the RPI with the sd-card and USB-disk still connected The RPI will now have it's root set to /dev/sda2 cat /etcfstab proc /proc proc defaults 0 0 PARTUUID=e4f3c2c9-01 /boot vfat defaults 0 2 PARTUUID=e4f3c2c9-02 / ext4 defaults,noatime 0 1 # a swapfile is not a swap partition, no line here # use dphys-swapfile swap[on|off] for that ===== Luc -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/69b6640f-7752-430b-8fe9-d50539243ff9%40googlegroups.com.
