Is a mdadm check on your trusty software RAID array happening at the worst time and slowing down your server or NAS?
Personalities : [raid1] [raid10]
md127 : active raid10 sdb4 sda4
897500672 blocks super 1.2 2 near-copies [2/2] [UU]
[==========>..........] check = 50.4% (452485504/897500672) finish=15500.3min speed=478K/sec
mytop is one of my favorite tools and it is fairly simple aside from a few caveats and issues that persist to this day.
To install it on Centos:
yum -y install centos
Install the "Flashblock" plugin because we all know most unwanted high CPU usage situations come from the browser usually because of a looping Flash ad taking up 100% CPU.
The solution is to install the "Flashblock" plugin that doesn't allow any Flash to load and play unless you click on the placeholder.........
If you have a webserver and find you have high IO/lagginess MySQL is one of the first things to check. It turns out MySQL was my problem and it was creating a high load on my server, especially for IO.
How to Enable MySQL Slow Query Logging To Find Slow Performance/Queries
Add this anywhere under [mysqld]
log-slow-queries = /var/log/mysql/mysqlslowqueries.log
long_query_time = 1........
I'm using Ubuntu 8.04 but anyone using older kernels will find this may apply to them. My Intel graphics are very slow with the default Xorg settings but by using "EXA" acceleration, scrolling down windows of text becomes pretty snappy.
Just edit /etc/X11/xorg.conf
Identifier "Configured Video Device"