I have a team of people using Zabbix, we occasionally get reports about swap usage being too high (it's a good report, there is a real problem).

So they go to the standard Swap usage graph.

It shows two things:
1. Template OS Linux: Total swap space = system.swap.size[,total]
2. Template OS Linux: Free swap space = system.swap.size[,free]

But, with a title of "Swap usage", what it should show is:
1. Template OS Linux: Total swap space = system.swap.size[,total]
2. Template OS Linux: Used swap space = system.swap.size[,used]

Except, there's no such value ([,used]) in the system.

Expected:
1. system.swap.size[,used] as a thing
2. the template(s) should be switched to use that.

It would be nice if there was a workaround. In theory if Zabbix allows for calculated values, one could calculate system.swap.size[,total] system.swap.size[,free] – and this could be a nice demo of that if it's supported. (If it isn't supported, someone should feel free to create a ticket asking for this.)