Doesn't sound the same - but we lost Portal also. All other servers were fine.
At a minimum, we found that
C:\Program Files\ArcGIS\Portal\framework\runtime\tomcat\conf\server.xml
and
D:\arcgisportal\content\items\portal\properties.json
were both corrupted (no content)
Recovering these files still wasn't enough to revive Portal so we had to revert to a VM backup.
Waiting on Esri support to see what damage this might have done to our hosted services which currently aren't running. Luckily most of our content isn't hosted - and they are working fine.