Server slow, but CPU, Memory fine

Posted on September 3, 2014

This started happening since a few days ago, and I am pulling my hair because I can’t figure out what is causing this. The server is working fine, but it seems to have slowed down because I see that the website is not as responsive as it was before (there is only one bigger website on the server). The cron jobs take 3 times as much to execute as before, and when I try to connect to the server by SSH, it takes a while for me to connect. All in all, things have slowed down in general. The weirdest things though is that CPU and memory usage are actually low and within the boundaries where they were before this started occurring. The bandwidth also seems to be in the normal boundaries.

I am checking the processes running, and I see that Apache and MySql take up most of the resources as before. But again as before, they are in the normal boundaries.

I am really baffled by this and I really don’t know what to do any more. Could someone please help as this is a very important server for me?

FYI, I am running Cent OS 6.5 x64. Thanks!

This textbox defaults to using Markdown to format your answer.

You can type !ref in this text area to quickly search our full set of tutorials, documentation & marketplace offerings and insert the link!

These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.

Hieuhau81

October 21, 2016

This comment has been deleted

Moisey Uretsky

September 5, 2014

You would surprised how many command line utilities rely on DNS resolution at this point in time so if you’re /etc/resolv.conf is out of date or has bad entries that are unreachable it can cause the server to feel horridly slow when in fact nothing is actually broken. That’s because it’s querying nameservers and has to wait for the timeouts before it can continue.