We've been doing a lot of load testing recently and are planning on doing a lot more, so we've developed a simple little script to make the collection of the vmstat (performance statistics) a bit quicker.

multivmstat is a php command line script which makes it easy to collect the statistics. Download the script

To run it you specify a list of servers to check:

This will run vmstat on each of the servers with a 5 second interval between samples.

It will create the following files:

Note: You mush have ssh access to each machine - ideally with a certificate so that no interactive authentication is required.

Download the script

I've been playing around with CakePHP again (I looked at it a couple of years ago) for a small site I'm working on.

I came across this lovely error though when trying to do a redirect:

I couldn't see anything wrong with the code - but a quick google found the solution - I had extra whitespace in the controller which was causing the problem.

Removing the extra whitespace after the closing ?> tag fixed it up.

Update: As Danilo pointed out below - this is not a cakephp issue, but a general php one, which occurs if you try to send headers after anything has been output to the browser.

Cheers, Mark

One of the nice things about Ubuntu is how easy it makes it to upgrade between versions - typically start up update-manager and it will prompt you if there is a new version available and handle all the details of the upgrade for you. I've done numerous upgrades this way and never had any issues.

However, I have a number of ubuntu servers which I manage and previously I have upgraded them by changing the /etc/apt/sources.list and then running "sudo apt-get dist-upgrade"

Today I discovered that there is an automated script to handle it - which I presume is what powers the gui version behind the scenes.

You need to make sure you have update-manager-core installed:

Then you simply run do-release-upgrade

I've just upgraded two different servers from Feisty as it has recently stopped being supported. I upgraded them to Gutsy and then to Hardy which is a Long Term Supported version. The whole process took about an hour of which it took about 5 minutes of my attention to answer a few simple questions.

Who said Linux is hard :-) Cheers, Mark