I believe the max limit should be 128. I don't have a S4810 available to me, but that's what Im getting from a S4820 and would expect it to be the same. You might try issuing the command "show int po ?" This command gave the upper limit in its output for me.
hi all, how many port-channel i can create under one VLT domain. TOR swiches configured with VLT domain. i want to connect 8 more switches. to tor.    [IMAGE]  
S4910 VLT port channel limitation