unable to downsize the root filesystem in ubi format under a certain level

    Hello,


    I noticed that if I strip down the "fsimx6sx_min_defconfig" I am limited of the filesystem size to 7110656 bytes, when I am using buildroot.


    So for example I create a system and load it to check the disk free space: I see that I only use 5.1 MB (see [1]). But the created and loaded ubifs image is bigger than this (~7 MB, see [2]).



    Does this have to so with the options:

    BR2_TARGET_ROOTFS_UBIFS_LEBSIZE

    BR2_TARGET_ROOTFS_UBIFS_MINIOSIZE

    BR2_TARGET_ROOTFS_UBIFS_MAXLEBCNT


    I also checked the docu under [3], but could not find a suitable answer. For example how can I create a ubifs image that takes only 3 or 4 MB of space?



    [1]:

    # df -h

    Filesystem Size Used Available Use% Mounted on

    ubi0:rootfs 214.1M 5.1M 209.1M 2% /

    …


    [2]:


    $ du -b output/images/rootfs.ubifs

    7110656 output/images/rootfs.ubifs


    [3]:

    https://bootlin.com/blog/creating-flashing-ubi-ubifs-images/