OpenWrt founder here; you&#x27;ve pretty much hit the nail on the head.<p>Due to size constraints most platforms use a split filesystem consisting of a large read only root filesystem and a smaller overlay for changes. The read only filesystem allows for much better compression ratios but it also means if you attempt to replace an individual package you&#x27;ll end up with two copies, original in the RO and new in the overlay.<p>Reflashing an OpenWrt device generally consists of migrating a minimal environment over to a ramdisk, rewriting the kernel and read only portions and then writing a backup of the config files to the overlay. On failure you&#x27;re likely to be stuck in whatever rescue mode the bootloader provides.