How to upgrade rootfs(ubifs) in linux

[guochgz]

hello, everyone:

      I have a custom board with imx6ull,  there is four patition.

      1. uboot partition

      2. kernel partition

      3. dtb partition

      4. rootfs partition (ubifs)

     now I need to upgrade this system when the system is running. but at this time, the /dev/mtd3 is already mounted by kernel. when I flash_erase this partition(rootfs), all the bins(executable programs) will be lost.  and the status of /dev/ubi0_0 is "Device or resource busy" .

     what am I supposed to do? 

[b36401]

You can create another rootfs partition for upgrade.
I mean you can make a small OS that can perform the upgrade of original rootfs and place it on separate one.