Router won't boot if config directory is symlinked to overlay-boot

Installing and Using OpenWrt
1

Router fails to boot if /etc/config/ is a symbolic link pointing to /overlay-boot/upper/etc/config/ (ln -s /overlay-boot/upper/etc/config/ /etc/config). Presumably because the device tries to access the config directory in the middle of mounting the USB stick and the old overlay /overlay-boot

# /etc/config/fstab on /overlay-boot, symlinked on /overlay
config 'global'
        option  anon_swap       '0'
        option  anon_mount      '0'
        option  auto_swap       '1'
        option  auto_mount      '1'
        option  delay_root      '5'
        option  check_fs        '0'

# Original overlay partition, mounted as /overlay during boot
config 'mount'
        option  target  '/overlay-boot'
        option  device  '/dev/mtdblock3'
        option  fstype  'jffs2'
        option  options 'rw,sync'
        option  enabled '1'
        option  enabled_fsck    '0'

# External overlay partition, increases the available disk space on the router
config 'mount'
        option  target  '/overlay'
        option  uuid    '186f37df-2f8f-4283-919e-cb4a14b59097'
        option  enabled '1'

config 'swap'
        option  uuid    'd98414f9-a8e7-4df0-b353-fb4677d511a7'
        option  enabled '1'

What is causing this? I need to deduplicate the config directory so that the router can operate under the same configs with or without the the USB stick.

2

One approach might be to just overlay the "USB config" on top of the "stock" overlay.

3

This is what I do currently, the problem is that when I take the usb stick out, the configuration for things like vlans becomes outdated and generates problems. The idea is that config files should always be read from internal memory, so I don't have to sync them manually.

4

Ah, so you want the USB stick to overlay everything except /etc/config/ (or perhaps all of /etc/, as there is "config" there as well, or perhaps "the following directories" or ... ).

If only a few directories, I'd handle that with specific overlay mounts. I'll have to think if there's a "clever" way to achieve a few "holes" so that the writes go to the underlying file system instead.

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