Defrag your hard drive!
As mentioned in Scott’s blog, “Getting the most from your NetFlow and sFlow Analysis Tool“, disk fragmentation can be the primary cause for slow performance in running NetFlow reports.
Due to the large volume of data stored when collecting NetFlow packets, disk I/O may already be pushed to the limits on your server. Add to that a highly fragmented disk drive and you might as well go hang out at the water cooler while you wait for your report to run.
Here’s an example of an extremely fragmented disk:
As Scott mentioned in his blog, “With hard drives, blue is a good thing, red is bad. Ideally we would want to see mostly blue and white.”
But, on the other hand, if you don’t have anything better to do with your time, if using Scrutinizer has so streamlined your network monitoring that you need to slow your day down a bit, then please, leave your disk fully fragmented and take a break!
Otherwise, if you prefer your Netflow reporting to complete in your lifetime, then defrag!
And in the spare time that you now have to kill, you can monitor excessive Facebook traffic and other odd traffic patterns on your network, or read our blogs to learn how to enable Flexible NetFlow, or give us a call to find out what else our NetFlow solution can do for you.