DR excercise with image Backup

I just want the share the experience we had last week when we were doing our Annual DR excercise for our systems

1.There are daily backups(hotbackups) to tape and also entire system image backups..These backups were taken when the DB was running

SUNDAY--Hotbackup
Rest of the Days--Archivelog backups



We did restore the image backups along with tape backups on Saturday
We had 2 production database , 1 was heavily utilised and the other one was just sitting idle..

When we try to start the DB , the database that was idle came up without any issue but the Heavily accesed database didnt comeup...with error messages FUZZY backup..File header verification failed.....

Next Step

1. Resored the Sunday Full backup
2.Restored all the archivelogs upto saturday

I tried restoring a particular file from the backup and applied all the logs but when the point where the backup was taken reached , the redolog has corrupted datablock and the recovery halted....couldnt open the DB but need to restore the entire db from the hotbackup...

Erros
Fuzzy backup
header verification failes....


Do rely on image backups in case of Disaster ..