How to measure boot time?

Question

I was wondering what is the "proper" or "most significant" way in which to measure the boot time of a client machine:

• From turn on to login prompt
• From turn on to login prompt (HDD light off)
• From turn on to browser open (HDD light off)
• From turn on to 3 most commonly used application open (HDD light off)

etc...

I generally use the third, as this measures the time before the system becomes usable and useful. What do you think?

Solution 1

I would measure the time from the point that POST ends to the time that an automated login completes and the user is able to use their most frequently used application (ie: Firefox,etc). Waiting for the hard drive light to stop is mostly meaningless with background indexing and read ahead related tasks, your hard drive may not stop activity until several minutes after you're actually able to begin using your computer effectively.

If you're doing this on Linux you can try Boot Chart, it will help you identify what's taking so long to boot.

http://www.bootchart.org/

The main thing is to be consistent in your measuring methodology so that if you tweak anything you're comparing apples to apples.

Solution 2

I think boot time is generally measured as when you get your login prompt and can start interacting with the operating system, as the OS has background services running, you can interact with it, and if you're launching applications to measure "usefulness" you're introducing variables that the OS manufacturer has no control over (they didn't make firefox, or other applications you commonly use, so it's not their fault if the libraries/etc. are slow to load).

If you're benchmarking the OS's boot performance, you measure what the OS is taking up in time before it's telling you "Hello, world!"...the login prompt's time to begin taking input.

Solution 3

I don't know if there's a standard for this, but personally I consider my system to have 'booted' when I am able to open the start menu (or dock) and start an application. Before that point I don't really consider the system usable.

That said, I imagine any manufacturers that are quoting boot time are quoting the shortest possible time, which will be to login prompt, or desktop appearing I would imagine.

Comments

[djangofan]

I saw a software program the other day on my local news that seemed to be able to create a chart of the start time of each individual Windows system service and showed the order of them starting up. I don't remember the name of it though...

[Ciro Santilli Путлер Капут 六四事]

Up to start of init howto subset: stackoverflow.com/questions/12683169/…

[John Gardeniers]

Good point, there is no defined point at which a system will be considered booted by all users. You're interpretation is the only one that makes sense to me.

[dmoisan]

Network timings for this purpose are going to vary. A lot. So much that you might not be able to make a conclusion from just that. Much better if you have a kernel log or Windows system event log.

[mas]

@dmoisan: Why not both? I would expect that if you want to do this that much of the infrastructure (DNS servers, boot servers, content servers) that would be measured in the tests are local (in the same building or campus) or no more than a single WAN hop away and under your control. I wasn't including tests of internet-hosted resources as these are much more variable. Even so, if variable-time resources are needed before a device is fully available to the user then samples of timings in different load conditions will still be helpful for informing the help desk and for future fault-finding.