What trigger parity check?

[Muath]

Hi, 

 

I have a small question, What triggers parity check?
for me, I set it up to work every 2 months but it keeps working every time and then!
first time when I had a power outage and it's good to trigger it 
but also it's worked after I stopped the array two consecutive times since I was playing with some setting that needs the array to be stopped

Is this what caused the parity to be checked?
Are there other causes to trigger parity check?

 

Thanks 🌹 
 

[Squid]

Unclean shutdowns

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