Back Up your Certificates on Plesk

Global Support Centre > SSL Certificates > Plesk > Back Up Certificates

Plesk stores the SSL related files in a httpd.pem file inside a "cert" folder. Both the RSA private key and Certificate are kept inside this file the path to which is: /home/httpd/vhosts/domain.com/cert/httpd.pem

Backup the the RSA private key from this folder.