Moving /home and /tmp to external drive on OrangePiPlus

aik · February 9, 2023

I have this small 64bit H6 orange pi and SSD connected via USB, runs "Armbian 22.11.4 Jammy". Now I am trying to move /home and /tmp to the USB mounted drive to save RAM and move lots of writes from an SD card to a bigger and more capable external SSD.

I uninstalled overlayfs, disabled tmp.mount and whatever there was with "tmp" in the service name.

aik@hass:~$ cat /etc/fstab 
UUID=ecc7fb6d-12ab-41b9-b11a-c2c9b78e3bd1 / ext4 defaults,noatime 0 1
/dev/sda2 none swap defaults 0 0
/dev/sda3 /mnt/sda ext4 defaults,sync 0 0
/dev/sda4 /tmp ext4 defaults,sync 0 0
aik@hass:~$ cat /proc/cmdline 
root=UUID=ecc7fb6d-12ab-41b9-b11a-c2c9b78e3bd1 rootwait rootfstype=ext4 console=ttyS0,115200 console=tty1 consoleblank=0 loglevel=1 ubootpart=167303c8-01 usb-storage.quirks=0x2537:0x1066:u,0x2537:0x1068:u   cgroup_enable=memory swapaccount=1
aik@hass:~$ systemctl | grep sda
  sys-devices-platform-soc-5311000.usb-usb2-2\x2d1-2\x2d1:1.0-host0-target0:0:0-0:0:0:0-block-sda-sda1.device loaded active plugged   106X EFI\x20System\x20Partition
  sys-devices-platform-soc-5311000.usb-usb2-2\x2d1-2\x2d1:1.0-host0-target0:0:0-0:0:0:0-block-sda-sda2.device loaded active plugged   106X 2
  sys-devices-platform-soc-5311000.usb-usb2-2\x2d1-2\x2d1:1.0-host0-target0:0:0-0:0:0:0-block-sda-sda3.device loaded active plugged   106X 3
  sys-devices-platform-soc-5311000.usb-usb2-2\x2d1-2\x2d1:1.0-host0-target0:0:0-0:0:0:0-block-sda-sda4.device loaded active plugged   106X 4
  sys-devices-platform-soc-5311000.usb-usb2-2\x2d1-2\x2d1:1.0-host0-target0:0:0-0:0:0:0-block-sda.device      loaded active plugged   106X
  mnt-sda.mount                                                                                               loaded active mounted   /mnt/sda
  dev-sda2.swap                                                                                               loaded active active    /dev/sda2
aik@hass:~$ systemctl | grep tmp
● tmp.mount                                                                                                   masked active mounted   tmp.mount

Now there are 2 problems with this:

1. the root is mounted as readonly right after booting. There are no reported errors of any kind, just readonly. Remounting `/` with `rw` fixes it and it stays so for days.

2. /tmp from the above is never mounted at the boot time, have to `mount /tmp` manually but the other two mountpoints do mount.

So there must be some leftover from my removal of tmpfs's /tmp, what is it? I am lacking lots of systemd knowledge, it is soooo arrogant 😞

Also, /boot/armbianEnv.txt has `usbstoragequirks=0x2537:0x1066:u,0x2537:0x1068:u` which is added to the cmdline above, what is this about? The `sda` from `fstab` is `2537:1066 Norelsys NS1066`.

Thanks,

Edited February 9, 2023 by aik