Fire-fighting and troubleshooting...
I have occupied the role of Systems Manager three or four times in my career, in different industry segments, and as a consequence I have a great deal of experience in the sort of problems that can arise when infrastructure and operations fall out of sync. I have managed a UK-wide network using leased lines and multiplexes, run VLAN's over dark fibre, and managed a horrendous bodge-job created by a double acquisition across Europe. The challenges of being Systems Manager, as is the case with most middle management roles, is doing the best you can with the limited resources you have, human, physical and financial!
In the course of this I have gained substantial experience in the publishing world, manufacturing and sales, and also in the area of freight handling and logistics.
Each of these roles has required the use of my wit and wisdom to overcome the various challenges which seem to arise on a regular basis, whether it is caused by a change in government legislation, the increased demands of a new Sales campaign or just plain 'somethings broke, find a way round it'.
The good news is that in the course of this activity I have become familiar with several flavours of UNIX, the Windows architecture, and a huge variety of storage, backup and networking products and applications, plus the tools and utilities needed to keep them running.
By far the most important skill for anyone in the role of System Manager is the ability to deal with other staff members, whether it is ensuring you run a happy and productive team, or having the patience to explain to the Sales Manager why we can't analyse a Petabyte of data in 5 minutes...
Encouraging your staff to do their best even when you think they may deserve a good kicking, and presenting a rational explanation to the board who are baying for blood, requires years of zen-like training, and it is probably easier to learn to walk on a tightrope!
Prioritising, delegating, changing focus from the tactical to the strategic and back, staff development, budgeting, refresh cycles and forward planning all come in there somewhere, but the bottom line is simple: IT is there to support the business - it is your job to keep it working somehow.