A recent post in the vSphere forums asked what seems to be a simple question: How can I measure how long it takes to boot a virtual machine?

I believe that the poster was attempting to find out if there is a performance stat that can be used for this purpose.  However, it brings up a bigger question: What is boot time?  Is it:

• The time it takes to complete the full BIOS run?
• The time it takes to get to a login prompt?
• The time it takes to first see the desktop after a successful login?
• The time it takes for the user to be able to effectively interact with the desktop after a successful login?

For me, it depends.  If it’s a server, it’s the time it takes to get to a login prompt.  For a desktop, it’s the time it takes to get to a point where a user can effectively interact with a desktop after login.

What is it for you?