Is it normal or not?

Got a call to a store that had ice reported on their suction line on the roof. there was some ice on the suction line but ended at the service valve on a discus compressor. Talked to another tech about it and he said some say this is normal and some say it's floodback. Your running a 3 door reach in / walking in Freezer and it has to run a lot because it's getting stocks and shopped all the time. I haven't checked superheat yet and I'm going to but, just on the info here who thinks this is normal?

It could be ok and normal. Lets say you are maintaining -20f SST and have the recomended minimum 20f superheat at the service valve of your compressor. That's a 0f suction line, well below the freezing point of H2O.

Check your superheat at those compressors and then sell them some new Armaflex.