I agree with the need for an escape plan. The 2001 recession taught me that the emergency fund isn't an abstract concept, it's as important as paying your electric bill (I have used it to pay the electric bill).
I also agree with asking for better compensation.
Also, consider that, even if no extra compensation for added responsibilities is given, that there may be a huge value in new responsibilities. You might not get money now, but when you are looking for future jobs making more money, more doors may open because of the skills and experience you bring to the table. Somebody making a hiring decision might view a content producer with proven sysadmin skills as more valuable than a content producer who has always worked with a sysadmin.
Looking back, I'm hugely grateful to the younger me for not saying "that's not my job" and quietly building skills and experience.