[CentOS] Migrating from RHEL to Centos

[John R Pierce]

Hemraj S wrote:
> Hi,
>
> I m currently running my production servers on RHEL 4.6 & would like 
> to migrate to Centos4.6 as it has more benefits & advantages. I looked 
> at the Centos release notes available at 
> http://mirror.centos.org/centos/4.6/os/i386/RELEASE-NOTES-en.html and 
> understood that the basic difference between RHEL & Centos
> are look/feel related & binaries,functionalities are almost same. But 
> when i compared the sysctl values of RHEL4.6 with Centos4.6, i found 
> that there are lot of differences in the parameter values. Now my 
> question is:
>
> 1) Just like sysctl difference, is there any other difference between 
> RHEL & Centos which could vary the performance & needs to be taken 
> care during migration.
> 2) When the Centos packages are built, are they built with the same 
> configuration as in RHEL or is there any difference.

the defaults for sysctl should be identical if both systems are running 
the same kernel revision on similar hardware.   do a `uname -a` on 
both.     did your rhel4.6 system have anything in /etc/sysctl.conf ?    
CentOS is built directly from the SRPM's for the AS configuration of 
RHEL, using the exact same options.    the precise versions of the 
compilers and tools used may vary in some cases as upstream doesn't 
fully document their build process (RHEL version X is apparently not 
built on a stock RHEL version X development platform, using the supplied 
tools).