How to migrate NAS on Debian from Raid1 to Raid0?

Question

linux

There is a NAS with two physical HDDs. It has three sections:
/dev/md0 - Swap (512MB)
/dev/md1 - Rootfs (5GB)
/dev/md2 - User data (All unused space, not mounted by default)
Requires /dev/md2 to be transferred from Raid1 to Raid0 . According to the manual, everything is simple, you just need to run one command:

# If you need RAID-0 (Stripped):
# Warning! Data partition will be erased!
umount /dev/md2
mdadm --stop /dev/md2
mdadm --create --force /dev/md2 --raid-devices=2 --level=raid0 --run /dev/sda3 /dev/sdb3

After this command and formatting this partition, everything works fine until reboot. After the reboot, the server stops starting and falls into recovery, then when Reset is pressed, Raid1 is recreated and everything works fine again ... Only I need Raid0.
If you need more information, then maybe here: anionix.ddns.net/WDMyCloud/WDMyCloud-Mirror/Debian...
But it doesn't help me. Basically help!!!

Answer 1

If sclerosis does not change me, then these underNAS have 4 partitions per disk - swap, 2 systems and user data.
Also what hinders to make to make all operations through a web-muzzle?
> when you click Reset
Set the settings, reset the settings. Why aren't they saved?

Answer 2

backup all data to a third-party medium.
reformat the system to Raid0
Restore data to fs.
even your link says
# Warning! Data partition will be erased!
when converting partitions, the data is overwritten.

Answer 3

The resulting configuration must be saved in mdadm.conf.
Example: xgu.ru/wiki/mdadm#.D0.A1.D0.BE.D0.B7.D0.B4.D0.B0.D...