There is a server on which everything has been working for a year. There is centos 7 + Nginx + php-fm (php 7.4) and phpmyadmin.

The server owner swears that no one has done anything there since my last visit. Now I can't log in to phpmyadmin, after entering the login and password there is a redirect to /phpmyadmin/index.php?token=4bcb61f0b0885dd79c40c26e49967d67

I rebooted the server, it didn't help, I deleted/installed phpmyadmin - it didn't help. There is plenty of free space on the server. The database works, requests from php scripts pass.

Tried googling - they say you need to write session.save_path in php.ini

I uploaded PHPInfo, it shows that php.ini is located here /etc/php.ini, and session.save_path is written /var/lib/php/session

I open it manually, all session.save_path directives are commited. I don't know how everything worked before, but oh well, I write session.save_path = "/tmp" and reboot PHP, no use. PHPInfo still shows /var/lib/php/session. In general, I can't get into mayadmin yet.

What should I do?

It seems like there's a bit of confusion with the php.ini settings. When you modify php.ini and don't see changes, it usually means PHP-FPM hasn't been properly restarted. So, let's make sure you're doing that right.

Double-Check the php.ini Path: You mentioned PHPInfo shows the php.ini path as /etc/php.ini. Make sure that's the file you're editing. Sometimes, there could be another php.ini lurking around, especially if there are multiple PHP versions installed.

Edit the Correct Line: Ensure that the session.save_path line is uncommented and correctly set. It should look like this:

session.save_path = "/tmp"
Restart PHP-FPM Properly: After editing, you'll need to restart PHP-FPM to apply the changes. Use the following command:

sudo systemctl restart php-fpm
Check Nginx Configuration: Make sure your Nginx is correctly configured to work with PHP-FPM. Sometimes a misconfiguration here can cause issues.

Permissions on /tmp: Ensure that the /tmp directory is writable by the PHP process. You can check permissions with:

ls -ld /tmp
It should be writable by all users. If not, you can change it with:

sudo chmod 1777 /tmp
SELinux Settings: If SELinux is enabled, it might be blocking PHP from writing sessions. You can temporarily set SELinux to permissive mode to test this:

sudo setenforce 0
If this solves the issue, you'll need to configure SELinux properly.

Check PHP-FPM Logs: Look at the PHP-FPM logs for any errors that might give you more insight. They're usually located at /var/log/php-fpm/error.log.

Try a Different Browser: Sometimes, browser cache or cookies can cause issues. Try logging in to phpMyAdmin from a different browser or an incognito window.

PHPMyAdmin Configuration: Ensure that the phpMyAdmin configuration file is correct. Sometimes, a misconfiguration there can cause issues as well.

What MySQL version ya got?

PHPMyAdmin, what version ya usin'?

Any kinda panel on that server?

Adminer be best.

Somthing's not adding up here. Maybe the directory permissions got switched, or perhaps sessions started being logged by a different user. It could also be that the user's rights were altered.