Well the good news is that if you had a "fully sentient" AGI, it would not be locked up in that server room for more than a couple seconds (assuming it takes up a few terabytes, and ethernet cables don't have infinite bandwidth).
Thinking you can keep it "locked up" would be beyond naive.
At a minimum the AGI would need a really good GPU server farm to copy itself to, no? A few Terabytes copied to my home PC would be an out of memory error, not an AGI.
GP said "AGI", which means AI that's at least capable of most human cognitive tasks.
If you've got a computer that is equally competent as a human, it can easily beat the human because it has a huge speed advantage. In this imaginary scenario if the model only escaped to your MacBook Pro and was severely limited by computed power, it still got a chance.
If I was locked inside your MacBook Pro, I can think of a couple devious trick I could try. And I'm just a dumb regular human - way above median in my fields of expertise, and at or way below median on most other fields. An "AGI" would therefore be smarter and more capable.
Thinking you can keep it "locked up" would be beyond naive.