Could not allocate block

ERROR: core-image-minimal-1.0-r0 do_image_wic: ExecutionError('build/tmp/work/.../core-image-minimal/1.0/temp/run.do_image_wic.1471812', 1, None, None)
...

| Writing inode tables: done 
| Creating journal (4096 blocks): done
| Copying files into the device: __populate_fs: Could not allocate block in ext2 filesystem while writing file "cc1"
| mkfs.ext4: Could not allocate block in ext2 filesystem while populating file system
| 512
| 
| WARNING: exit code 1 from a shell command.

Not related to free space in image size. Tested with:

    IMAGE_ROOTFS_EXTRA_SPACE:append = " + 150000"
    IMAGE_OVERHEAD_FACTOR = "2"

Conclusions:

• It is related to build on ZFS. In this case LXC on Proxmox's LXC.
• It works before.
• It works for another (bigger) image.
• It is related to wic image.
• Yocto's image.bbclass was fixed to correctly calculate sizes on compressed ZFS:
  • Problem raised here: image.bbclass - get_rootfs_size
  • And fixed here:
    • lib/oe/utils: add directory size function
    • classes/image: use oe.utils.directory_size() instead of du
• Problem still exists in poky/scripts/lib/wic/partition.py
  • Task do_image_wic.
  • du returns real disc usage (135649) (on compressed ZFS) instead of data size (250920).
  • adding –apparent-size fixes the issue (du_cmd = “du -bks %s –apparent-size” % rootfs_dir)