I'm capturing s_vi cookie value into eVar1. Used DTM to set this variables, under global variables section. But, getting none in the report when i choose visits as the metrics. If i choose instances as the metrics then there is no "none" in the report.
s.eVar1="D=s_vi" // captures the s_vi (visitor ID) cookie value in eVar1
Is it because, i am looking only s_vi cookie value? Should i need to write the condition and look for s_fid value if there is no s_vi cookie?
Reading cookies through Dynamic Variables is no longer supported for security reasons. Visitor ID has been added to Data Warehouse by default so you can pull a report based on visitor ID there. In Data Warehouse you also won't run into the uniques being exceeded like you will in Analytics.
For clarification, this answer specifically relates to passing the s_vi cookie into a variable. (D=s_vi) other dynamic variables may still work if they do not read the cookie.