Server won't physically fit in rack: which technical problems will I face in future if I force the mount?

Solution 1:

Recycle an old server rack?

Arguments against

Unsafe : someone could injure themselves by colliding with a server that should not be there.
The doors are now more of a hindrance than a help and should be removed.
No doors = no security. Defeats the purpose of having a rack.
Maintainance of older racks is more time-consuming than more modern racks.
Looks (and is) unprofessional and does not give a good impression.
You should use up-to-date standardized equipment so you can add and remove servers seamlessly.
Relocating an open rack to another room or site will require more time and effort.
Keep dust out and servers live longer.

Arguments for (devils-advocate)

An old rack is better than no rack.
No doors = better airflow (for old racks anyway) :D
Will the old servers even fit into a new rack?
The old servers and, presumably, operating systems must serve some useful function that may not be smoothly migrated to new hardware.
Even if there is more dust the old servers are probably not that valuable and cheaper to replace one at a time.
There may be plans to replace them in the next couple of years anyway.
The server room itself should be secure.
There is no money left in this years budget (or other cashflow issues).
Perhaps old rack is mostly unused and space is cheap.

Mounting safely inside the rack

To make it possible to close the doors consider mounting the server in one of the following arrangements (assuming old server is 4u):

vertically at the front side of the rack with the front on top so drives bays are accessible if this is more important

Real-estate Penalty: 13u = 16 modern servers that could fit where that old server goes and 13u are wasted.
vertically at the rear side of the rack with the back on top so cabling is more accessible

Real-estate Penalty: 13u
My favourite: diagonally and proudly show it off.

Real-estate Penalty: 7u (approx.)

This may increase your changes of getting a new rack sooner (but I would not like to have to look at that every day!).

enter image description here

Solution 2:

Racks are inexpensive and can purchased used or refurbished. It's nearly impossible to go wrong with a modern rack. The cost of doing this the right way is so low that any janky, tacky or unprofessional solution is just adding to your technical debt.

Temporary workarounds always seem to become permanent or otherwise end poorly. A good example is this server installed in a rack without using rack rails. Shortcuts end up causing more time to you or someone else in the long run.

enter image description here

That should be reason enough. (and maybe avoiding an appearance on http://thedailywtf.com)

Solution 3:

In any kind of rack with a chimney or fans based at the top, the proper airflow depends on having the rear doors closed (and the front correctly blanked).