On 01-12-2020 09:45, c.buhtz@posteo.jp wrote:

I think my missunderstand depends also on my bad english?

Am 30.11.2020 21:51 schrieb antlists:

quoted

On 30/11/2020 20:05, David T-G wrote:

quoted

You don't see any "filesystem" or, more correctly, partition in your

   fdisk -l

output because you have apparently created your filesystem on the 
entire
device (hey, I didn't know one could do that!).

That, actually, is the norm. It is NOT normal to partition a raid array.

In my understanding you are contradicting yourself here.
Is there a difference between
  "create filesystem on the entire device"
and
  "partition a raid array"
?

Yes, they are not the same.

   "create filesystem on the entire device"
you create a filesystem on the raw device, like with "mkfs.xfs /dev/sdc" 
or "mkfs.xfs /dev/md0"

a lot of people do this with raid devices, but it is rarely if ever done 
directly on HDD. afaik most installers will do this with raid devices, 
but never with normal HDD

"partition a raid array"
this means creating a partition table on the raid array, i.e. "fdisk 
/dev/md0" and creating partitions on it.
Here opinions differ. I am someone who often does this, and has 
production machines with partitioned raid :)

wols thinks it is not to be done.

Cheers

Rudy