I made a complete backup of Firefox, I used mozbackup, while on windows 7. How do i restore a mozbackup made archive(.pcv) in Ubuntu using Firefox?
I can't test this right now, but assuming mozbackup is just an archive, rename the pcv extension to zip, extract it and move the files to your profile folder.
Your profile is located under:
Looking at the support section of the website there is no version for linux,
Ref: Mozbackup FAQ
Without trolling through the site to see which format the program backs your data up I would recommend backing up your profile from firefox then restoring it in Ubuntu.
There is a very detailed support section from Mozilla here on how to achieve this.