RAID is degraded

[Brutaldeath]

Hello,
Since 3 time my RAID is degraded.
The first time, I have changed disc 5HDD1) that cannot send temperature but in interface, all my 4 disc have statut "Good"
I dont know why but if i put a new disc for replace HDD1, i restaure my RAID and 24h next, I have exactly the same probleme.

My RAID is degraded and I dont see temperature of my disc.
Only with HDD1
I have try with again another disc (3rd) It's the same probleme.

Can you have a solution ?
Why my RAdID is degraded ?
Why I cannot see temperature of 3 disc in same location?

[TMzethar]

In the process of replacing the hard disk, the operation of pulling out the hard disk will of course degrade the RAID level. Please continue to edit the storage pool and use the new disk to repair it.
As for the temperature problem you are encountering now, we will continue to keep an eye on it.
You can collect a system report at TOS-Technical Support-Issue Report, and then send it to us for analysis through the network disk link.

[Brutaldeath]

In the process of replacing the hard disk, the operation of pulling out the hard disk will of course degrade the RAID level. Please continue to edit the storage pool and use the new disk to repair it.

Only the 1st one is an "old" disc (approximately 5 years) but I dont have any error if I put it in dock and make read/write test and smart test with my computer (USB dock with the 1st disc on Win 10). I don't have any errors / problems.

I have try with 2 other disc (new) and I have exctly the same probleme. Still 12 or 24 hours, RAID is degraded and I dont see the temperature in the HHD1
I have try to put the 2nd disc on another bay of the NAS and I don't have errors

For the moment, i have succesfully restore the TRAID and I dont have degraded RAID and I see temperature of the disc. The last repair TRAID have finished this morning 3:15 AM

[Gremlin]

{L_BUTTON_AT}Brutaldeath

That's good to hear. Did you do anything differently this time?

[Brutaldeath]

No, but NAS turn on since 12hours, i'm waiting 2 or 3 day for sure that not restart...

[thatsnotmynaim]

I've just had something similar, degraded TRAID, disk #5 not showing temperature and on rebooting system disk #5 had gone.
Removed disk #5 from NAS, placed in HDD caddy on Windows PC, Hard Disk Sentinel tools showed the disk was 100% fine, so wiped the drive and reinserted it into the NAS. Did a rebuild failed drive and system and TRAID have worryingly instantly fixed itself, almost zero time to rebuild, even though drive had been completly wiped using CLEAN in DISKPART. I now do not trust my system and I also want to replace another disk #6 with a bigger drive but am scared to do this incase the TRAID is not fine despite it saying it is..