Linux Performance Observability Tools

I found this image from Facebook (It seems facebook is not providing gossips only :-) which is very useful for Linux system administrators in finding issues in the systems.

I have downloaded the image from its original site (Site owner Brendan D. Gregg) and the original site http://www.brendangregg.com/linuxperf.html


A big thank to Brendan D. Gregg for publishing this.

iptables Issue in CentOS7

I had issues in enabling iptables in CentOS7. After following the post (link given below) I was able to resolve the issue I had with enabling iptables.

Error I got when I tried to enable iptables

server1#systemctl restart iptables.service
Failed to issue method call: Unit iptables.service failed to load: No such file or directory

Following is the screen shot of the answer received through the post http://stackoverflow.com/questions/24756240/how-can-i-use-iptables-on-centos-7