Yes. You can recover your Plesk password on your Linux dedicated server.
To Recover Your Plesk Password on a Linux Server
1. Using SSH, log in to your server with the User ID and Password that you created when you set up your dedicated hosting account.
2. At the command line, type su -.
3. For your password, use the same password that you use with your User ID.
4. Type cat /etc/psa/.psa.shadow
This file contains your admin Plesk password.
Starting from Parallels Plesk Panel version 9.x password can be changed with the utility init_conf
# /usr/local/psa/bin/init_conf --update -passwd newpasswd
SUCCESS: Update of administrator's information complete.