[CentOS] Migrating From CentOS-6 To CentOS-7

Wed Nov 29 06:20:00 UTC 2017
Eugene Poole <etpoole60 at comcast.net>

I've a system that has been running CentOS 6 64-bit for almost 4-years 
and I want to start the move to CentOS 7 64-bit.

I run software RAID-1 with LVM everywhere except /boot which is a 
standard partition RAID-1.  There are 2 areas that concern me greatly 
about this migration:

1.  How do I duplicate my current grub configuration file that supports 
a failure of /dev/sda to grub2?

2.  How do I install CentOS 7 but use my existing hard drive layout so I 
only format specific OS file systems.  My drive layout goes back to the 
original proposed FHS layout.  The separate partitions are:

/boot        1GB

/                 6GB

/home        4GB

/opt            4GB

/tmp            2GB

/usr             12GB

/usr/local    2GB

/var              8GB

swap            16GB

Plus many other file system dedicated to specific applications and data.

When I moved from CentOS 5 to CentOS 6 all of the OS partitions were 
formatted except /home.  All went extremely well then.

But I don't see a way to do that with CentOS 7.

Is there some detailed installation instructions showing some advanced 



Eugene Poole
Woodstock, Georgia