Only the following switch models support sFlow:
S2720-EI, S5720-LI, S5720S-LI, S5720-SI, S5720I-SI, S5720S-SI, S5720-EI, S5730-SI, S5730S-EI, S5735-L, S5735S-L, S5735S-L-M, S5735-S, S5735S-S, S5735-S-I, S6720-LI, S6720S-LI, S6720-SI, S6720S-SI, S6720-EI, S6720S-EI