From my experience sys admin work is hard to manage using scrum. I have used kanban or a combination of kanban and agile to track my work.

The training I attended said the ideal team size for scrum is 4 - 7 team members. I would say follow whatever makes you feel comfortable, as long as you deliver some value to your end users it is all good.

Having said that at my current work I am using a trello board to manage all my stories and find it helpful even though it is just two of us at the moment. If you have any more questions feel free

I am going to shamelessly promote my startup, check out http://askmeanything.me/ , to ask questions to founding engineers.