[systemd-devel] systemd blocks update kernel partition table

[e-stl at gmx.de]

Sorry for my html mail before!

Hi list,
i'm new to systemd and are working with an embedded device with yocto.
 
In my embedded device i want to format and store my emmc device with the new firmware. When updating the firmware the device boots from SD card.
 
When updating the firmware i want to (re)partition my emmc storage device with parted and 3 ext4 partitions. None of the partitions is mounted, because the device boots from SD card.
When the emmc already contains a partition table parted complains that it can't update the kernel partition table after it was modified.
It seems these partitions are already mounted anywhere. partprobe doesn't help either.
 
But i don't mount them and when i check for mounted partitions by mount command, none of them is mounted. The only thing i see is that systemd has created device units for these partitions. In syslog i see that the ext4 partition is recognized (also in /sys/fs/ext4 available). I assume that the systemd device units block the update of the kernel partition table.
 

I need to modify, format and fill the partitions on the emmc without booting after the new partition table is written.
 My question is: What/is systemd blocking the update of the kernel partition table and what can i do to prevent it?
 
Thanks in advance
Eberhard