Upgrade RHEL6 to RHEL7

RHEL upgrade.sh

yum update

reboot

## Repos configuration 
subscription-manager config --rhsm.manage_repos=1

subscription-manager repos --enable rhel-6-server-extras-rpms

echo “notify_only=0” >> /etc/yum/pluginconf.d/search-disabled-repos.conf

## Install upgrade tools
yum install redhat-upgrade-tool preupgrade-assistant preupgrade-assistant-el6toel7 yum-plugin-downloadonly

## Backup GRUB's RPM
yumdownloader grub

## Run Pre-Upgrade utility
preupg -v

## Check for upgrade conflicts 
preupg --riskcheck --verbose

## backup Shadow files
cp /etc/shadow /etc/shadow.backup
cp /etc/gshadown /etc/gshadow.backup

## Run the upgrade tool
redhat-upgrade-tool-cli --iso rhel-server-7.6-x86_64-dvd.iso --cleanup-post