Upgrading PHP 7.4 to PHP 8.1 in CentOS 7

If you have both PHP 7.4 and PHP 8.1 installed on CentOS 7, but you're unsure where PHP 8.1 is located (e.g., for CLI use or configuring services), you can locate it with the following steps:

1. Check Current PHP Version

php -v

2. Install EPEL and Remi Repositories

sudo yum install epel-release yum-utils -y
sudo yum install https://rpms.remirepo.net/enterprise/remi-release-7.rpm -y

3. Enable Remi PHP 8 Repository

First, check available PHP modules:

yum module list php

Enable PHP 8.1 (or 8.2 if needed — change version accordingly):

sudo yum-config-manager --disable 'remi-php*'
sudo yum-config-manager --enable remi-php81

4. Upgrade PHP

sudo yum update -y
sudo yum install php php-cli php-common php-fpm php-mysqlnd php-xml php-mbstring php-opcache php-json php-gd php-curl -y

(Add any other PHP extensions your application needs)

5. Verify PHP Version

php -v

6. Restart Web Server

For Apache:

sudo systemctl restart httpd

For Nginx with PHP-FPM:

sudo systemctl restart php-fpm
sudo systemctl restart nginx

In my case, I faced following errors while installing PHP 8.1

Error: Package: php-pecl-redis5-5.3.7-2.el7.remi.7.4.x86_64 (@remi-php74)
           Requires: php(api) = 20190902-64
           Removing: php-common-7.4.33-15.el7.remi.x86_64 (@remi-php74)
               php(api) = 20190902-64
           Updated By: php-common-8.1.29-1.el7.remi.x86_64 (remi-php81)
               php(api) = 20210902-64
           Available: php-common-8.1.28-1.el7.remi.x86_64 (remi-php81)
               php(api) = 20210902-64
Error: Package: php-pecl-redis5-5.3.7-2.el7.remi.7.4.x86_64 (@remi-php74)
           Requires: php(zend-abi) = 20190902-64
           Removing: php-common-7.4.33-15.el7.remi.x86_64 (@remi-php74)
               php(zend-abi) = 20190902-64
           Updated By: php-common-8.1.29-1.el7.remi.x86_64 (remi-php81)
               php(zend-abi) = 20210902-64
           Available: php-common-8.1.28-1.el7.remi.x86_64 (remi-php81)
               php(zend-abi) = 20210902-64
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

And the solution was to remove the PHP 7.4-specific packages such as php-pecl-redis5 before processing with the PHP 8.1 upgrade.

Below steps are what I did:

1. Remove the PHP 7.4 Redis extension:

sudo yum remove php-pecl-redis5

2. Then upgrade PHP to 8.1:

sudo yum install php php-common php-cli php-fpm php-mbstring php-xml php-mysqlnd php-opcache php-gd php-curl

3. Reinstall Redis for PHP 8.1:

Install the compatible php-pecl-redis version from the Remi PHP 8.1 repo:

sudo yum install php-pecl-redis

It will pull the correct version (e.g., php-pecl-redis-5.x or 6.x) compiled for PHP 8.1.

📌 Notes

• php(api) and php(zend-abi) are version-specific. They must match exactly for extensions to work.
• Use yum list installed | grep php to see what 7.4 packages are still lingering.