In the last weeks I played around with mdadm - on VMs, Odroid-Devices,
PCs - all with Debian 10.
I observed a (for me) curious behavior about the naming of RAID
devices.
I did "--create /dev/md0" all the time.
But sometimes it results in /dev/md127.
Sometimes it is /dev/md/0.
Sometimes it switches between upgrade of the kernel image (/dev/md127
become /dev/md0 and booting fails).
Googleing this topic brings up a lot of other users discussing about
that problem.
My current solution is to ignore the /dev/*-name and mount the
device/partition by its UUID.
Another often reported "solution" is to edit the mdadm.conf. But this
is not a good solution for me. mdadm looks in the superblock and knows
(nearly) everything. Each conf-file I need to edit keeps the
possibility for errors/mistakes/faults (because I am not a sysop/admin
but a simple home-server-wannabe-admin).
My Question is how this names come up? How does mdadm, the kernel or
what ever component is responsible here, decide about the "name" of a
raid device?
And which factors influence the re-nameing of such devices (e.g.
between boot or kernel-updates)?