If you're asking how do you get consumption in Snow without the ILMT connector, there were 2 other IBM connectors you can use; BigFix and something else but I can only find the ILMT and BigFix when querying now. [FYI BigFix is now owned and supported by HCL not IBM.]

https://community.flexera.com/s/article/UserGuideHCLBigFixInventoryConnector

If you're talking about assigning a metric called terabyte to your license records, you'll want to explore 'custom compare values' in the SLM web user interface user guide.

https://community.flexera.com/s/article/UserGuideWebUserInterfaceSnowLicenseManagerversion9en-us-v2