Converting JB folder to ISO

How much time it takes? I've tried to create ISO out of JB folder using irisman, and it's been stuck on "Computing LBA for 195 directory entries..." for around 50 mins. Is it normal? Or did my PS3 froze?
I'm using PS3 SS with HFW and latest HEN, irisman 4.84.5, game is MGS HD Collection (jb folder weighs around 20GB).
And if my PS3 froze, what is the safe way of rebooting it?