VIM5-2Y, VIM5-4Y, and VIM5-4YE support only 10G or 25G speeds based on the partitioning of the first port of the VIM (port 25 for 24 port switches, port 49 for 48 port switches).
To move between 10G and 25G modes, change the partitioning of the first port of the VIM to 4x10G or 4x25G, respectively. This will affect all ports of the VIM.
For 48 Port Switches:
configure port 49 partition 4x10G
configure port 49 partition 4x25G
For 24 Port Switches:
configure port 25 partition 4x10G
configure port 25 partition 4x25G