Thank you for your response.
The description of the switch says:
"In addition, the 2920 switch series supports up to four optional 10 Gigabit Ethernet (SFP+ and/or 10GBASE-T) ports, as well as a two-port stacking module. These options provide you with flexible and easy-to-deploy uplinks and stacking."
I will look into the DAC cable. That's a bummer!
Thanks for the advice on the disks.