Here is an interesting recovery situation. The customer was running Oracle 7.3.4 on a Windows NT platform. Now, this is not my favorite Oracle configuration, but it’s a solid, stable configuration so who am I to argue?
In any case, the client lost the Oracle installation drive, as well as the drive with a couple of the oracle tablespace files. He did not have backups of the Oracle installation, nor did he have backups of all of the data files. He did have most of the data files though, so I suspect that someone created data files on the wrong drives, and his backup wasn’t set up to back up the other drives (this is not uncommon by the way). This might sound like trouble, right? Well, not in this case … luck was really on our side.
First I tried to re-install and re-create the database on the client’s NT Server. This did not work. For some reason I could not install Oracle and create a database. I don’t know if it was a bad Oracle installation CD or what, but I could not get the Oracle database to start no matter what I did.
Finally, I copied a zipped copy of the Oracle database files back to my PC. Then, I used one of the most useful pieces of software for consultants that Microsoft has ever developed. That is, Microsoft virtual PC.
I installed my own copy of Windows NT into a Virtual PC (yes, I had fully licensed copy just sitting around), and updated it to the most current version of Windows NT. In the process, I discovered that in order to use Virtual Machine Additions, I had to be on the most recent version of Windows NT (Build 1381, Service Pack 6). Once I had the additions installed, I installed Oracle 7.3.4. (yes, I had a CD of that sitting around also).
On my home Virtual PC, Oracle installed and started without problems, which led me to conclude that the client had issues on his NT server or with his installation CD. This would not be entirely unexpected consider the age of both pieces of software.
I used the ‘create a database’ installation option, then pointed the init.ora to the copy of the database that was sent to me, it had the controlfiles and everything, except for the datafiles on the other drive. I was able to drop the missing datafiles (alter database datafile offline drop), and startup the database.
Evidently the datafiles weren’t required for the data that the client needed. I gave the client an export file of his data, and sent him the Virtual PC with his Oracle installation on a DVD. All the client needs to do if he wants to start the Oracle installation is copy the virtual PC to a modern operating system, install Microsoft Virtual PC, and start up his Virtual PC. The client was extremely happy because he had been wanting to upgrade this server for some time, but couldn’t because of the antiquated operating system and Oracle version that was installed.
The whole process went so well, that I have to recommend it for small data recovery operations. It gives the consultant the ability to do the work on his home PC, and he make mistakes without worrying about losing data.
You might not want to try this at home by the way, my home PC has 64 bit Vista, 8G RAM, and mirrored 500G hard drives. Not to mention the licensed copy of Windows NT I had sitting around. But it was an interesting exercise.