Gitlab user accounts disappeared after system drive resized in virtualized Ubuntu

Hi. I have problem with GitLab server. Our GitLab server is running in Ubuntu inside VirtualBox. Recently I was forced to enlarge system disc in order to creates pace for future commits. Nevertheless, this action caused GitLab server to forget all user accounts. Server web page load correctly but no single user account can be accessed: “Invalid Login or password.”. Looks like database is no longer available. Is there way how to fix this problem or should I try to restore backup from *.tar file?