Am 30.11.20 um 14:47 schrieb antlists:

On 30/11/2020 13:16, Reindl Harald wrote:

quoted

Am 30.11.20 um 14:11 schrieb antlists:

quoted

On 30/11/2020 12:13, Reindl Harald wrote:

quoted

but i fail to see the difference and to understand why reality and 
superblock disagree,

In YOUR case the array was degraded BEFORE shutdown. In the OP's 
case, the array was degraded AFTER shutdown

no, no and no again!

* the array is full opertional
* smartd fires a warning

Ahhh ... but you said in your previous post(s) "the disk died". Not that 
it was just a warning.

quoted

* the machine is shut down
* after that the drive is replaced
* so the array get degraded AFTER shutdown
* at power-on RAID partitions are missing

But we've had a post in the last week or so of someone who's array 
behaved exactly as I described. So I wonder what's going on ...

I need to get my test system up so I can play with these sort of things...

and that's why i asked since when it's that broken

i expect a RAID simply coming up as nothign happened as long there are 
enough disks remaining to have the complete dataset

it's also not uncommon that a disk dies between power-cycles aka simply 
don't come up again which is the same as replace it when the machine is 
powered off

i replaced a ton of disks in Linux RAID1/RAID10 setups over the years 
that way and in some cases i cloed machines by put 2 out of 4 RAID10 
disks in a new machine and insert 2 blank disks in both

* spread the disks between both machines
* power on
* login via SSH
* start rebuild the array on both
* change hostname and network config of one

for me it's an ordinary event a RAID has to cope without interaction 
*before* boot to a normal OS state and if it doesn't it's a serious bug