mvdsv has no restart console command, if I remember correctly.
on map changes, your (qw)progs.dat is flushed entirely and all globals are essentually reset.
You can make persistant variables using the server's localinfo, cvars, the serverflags field (you only get one though) or the parms of a player (which isn't really that sane a thing to do) - QW prefers localinfo.