Install the required packages

You will need to install the cifs-utils package to mount a network drive on an Ubuntu Linux system.

sudo apt-get install -y cifs-utils

For a Red Hat based system you will also need the cifs-utils package, installed by dnf

sudo dnf install -y cifs-utils

Create a mount point

Create a mount point for the CIFS share. eg.

sudo mkdir /srv/cifs/<share>      # where '<share>' is the name of the share you want mounted

Create a credentials file

sudo vim /etc/credentials.<share>   # where '<share>' is the name of the share you want mounted

Add the following contents to the credentials file, updating with your userid/password details to access your share.

username=<shareuser>
password=<sharepassword>

Make sure the credentials file is only visible to root

sudo chown root:root /etc/credentials.<share>      # where '<share>' is the name of the share you want mounted
sudo chmod 600 /etc/credentials.<share>

Add the mount to /etc/fstab

To mount the network drive permanently, you need to add an entry to the /etc/fstab file to ensure the share is mounted automatically when the system boots.

Open the /etc/fstab file in a text editor and add the following line:

//<ip address of your cifs server>/<share> /srv/cifs/<share> cifs credentials=/etc/credentials.<share> 0 0

Testing the mount

sudo mount -a
df -h

This should show the CIFS share mounted at the specified mount point.

You need to get to the latest update level on the CentOS systems. If the systems have been unloved you will likely find that they can no longer access the repos servers.

Change the baseurl to http://vault.centos.org/, comment out the mirrorlist as per this image.

You’ll need to do this in at least :

/etc/yum.repos.d/CentOS-Linux-BaseOS.repo
/etc/yum.repos.d/CentOS-Linux-AppStream.repo

Then you can perform the required upgrade :

dnf update
dnf upgrade

Then I suggest re-booting and you can then perform the AlmaLinux migration by :

curl -O https://raw.githubusercontent.com/AlmaLinux/almalinux-deploy/master/almalinux-deploy.sh
bash almalinux-deploy.sh

Then the following should show that you’ve converted OK

cat /etc/os-release

cat /etc/os-release
NAME="AlmaLinux"
VERSION="8.6 (Sky Tiger)"
ID="almalinux"
ID_LIKE="rhel centos fedora"
VERSION_ID="8.6"
PLATFORM_ID="platform:el8"
PRETTY_NAME="AlmaLinux 8.6 (Sky Tiger)"
ANSI_COLOR="0;34"
LOGO="fedora-logo-icon"
CPE_NAME="cpe:/o:almalinux:almalinux:8::baseos"
HOME_URL="https://almalinux.org/"
DOCUMENTATION_URL="https://wiki.almalinux.org/"
BUG_REPORT_URL="https://bugs.almalinux.org/"

ALMALINUX_MANTISBT_PROJECT="AlmaLinux-8"
ALMALINUX_MANTISBT_PROJECT_VERSION="8.6"
REDHAT_SUPPORT_PRODUCT="AlmaLinux"
REDHAT_SUPPORT_PRODUCT_VERSION="8.6"