@roday
Can you expand more on how the dmidecode command didn't work? Did it error out? Did it have any console output return? By default, dmidecode is not a default installed package, so you can check to verify if the dmidecode RPM package is installed:
# rpm -qa dmidecode
---
[root@robtest mercury]# rpm -qa dmidecode
dmidecode-2.12-5.el6_5.x86_64
---
If you find that this package is not installed, simply do a yum install (as long as your AMP can reach the internet, otherwise you may have to download the package and do the manual RPM install):
# yum install dmidecode
Once installed, try the command again and it should work as expected.