Virtualization Through Thick and Thin

“Back in the good old physical server days, you bought a server
system, added disks to it and, after a time, when you came close to
filling those disks, either you added more disks or replaced them
with larger ones. Times have changed in the virtual world. You can
still provision a static disk (Thick provisioning), which is
typically much too large for the workload and any reasonable amount
of growth. But, you do it to prevent that middle-of-the-night ‘disk
is full’ call. With thin provisioning, you don’t have to worry
about that call anymore. Or, do you?

“Thin provisioning is an option presented to you during the
virtual machine’s disk creation step. The “thin” option provided is
a dynamically expanding disk. Initially, the virtual disk only uses
as much space as needed and then expands as necessary during the
life of the virtual machine. And, what’s even better than that, you
ask. You can convert from a static disk to a dynamic (thin) disk
even while your virtual machine is running. This sounds like a
dream come true, doesn’t it? It is. But, if you aren’t vigilant, it
can be your worst nightmare but you won’t find that fact in any
marketing literature.”

Complete
Story