[NTLUG:Discuss] ext3 vs. XFS vs. ....

[steve]

 > Another curious, wild thought came to mind.  Anyone know how
 > expensive it would be to have an electric motor coupled to a
 > generator via a relatively large/dense cylinder such that the
 > computer was totally isolated from the external electrical
 > environment?

Large flywheels can be really dangerous - they can store large amounts
of energy - but if anything at all goes wrong (eg a bearing breaks or
something in the generator seizes up) - then all of that energy has to
go somewhere - and the 'somewhere' is generally bits of flywheel flying
off at insane velocities and embedding themselves somewhere undesirable!

The practicalities of containing the resulting death, mayhem and
destruction means that the flywheel won't be storing more than a
few tenths of a second or so of energy in any practical setup.

Motors and generators are each less than 100% efficient - so expect
to see your electricity bills double if you go that route!

The mental comfort that comes from being able to physically see that
you are disconnected from the grid comes at a price.

There are much cheaper, safer and more efficient ways to provide a
few seconds of backup power and power spike/surge/dropout protection
using modern electronics where the energy can be stored in something
relatively safe like a pile of car batteries.