>>If memory serves, your NAS is being used instead of local storage for your web site(s).
>>
>>If IIS can't talk to its files then sure, it could stop those processes that depend on it. It's equivalent to a hardware failure.
>>
>>That message you report is exactly what I'd expect in that circumstance.
>
>Yes, but I am still wondering why IIS would simply decide to shut the application pool down. Because, the NAS went back online in 5 minutes but it took longer for us to go in VPN, RDP, IIS and all 3-letter acronyms you can find (lol), to start the application pool back.

There are IIS settings for the app pool 'Rapid-Fail Protection'
I think the default is to shutdown if there are 5 failures within 5 miins.
You can change these values or disable the shutdown completely but it would be better to handle a timeout gracefully.....