Urgent - Lost two drives. Looking for advice. 1

[THoey]

Okay, my NT server running Oracle 8.1.7 lost two hard drives yesterday. Our administrators our repairing the file system as we speak, so I am researching my options while I wait. I was able to remote into the server and run a couple of tests before they started the CHKDSK utility.

I was unable to get to any of the four DB instances using Enterprise Manager or SQL*Plus. I looked at the services and they all showed that they were started, but when I stopped and restarted them, they errored out and then showed that they were started again, so I don't trust that the DB's ever came up.

I would normally try to research the process, but I am in a bit of a rush, so I am looking to your expertise. While I am waiting for the administrators, I have a hundred questions, but I'll start with a couple:

1. I have been doing a weekly cold back up. I verified that I got all of my files over to the other server this past Sunday, so I think I am fairly safe as far as data goes. I have never had to restore from a cold back up, what are the basic steps? Do I need to drop the old database instances, recreate the instances, stop them, copy
the data files over top of the new files and then restart the instances?

2. Until CHKDSK is complete, I won't know if there is any corruption to Oracle. Would it be safer to completely reinstall Oracle?

3. We have been looking to migrate / upgrade to Oracle 9i soon. Is now as good a time as any? I am not sure if we could import the structures and data from a cold back up file like this. I am thinking I need to go back with 8.1.7 and then migrate / upgrade at a later date.

Sorry for all the questions, but thanks in advance for your help. Terry
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[THoey]

As a slight monkey wrench, our IT Staff just came back and offered up a new server, bigger, faster, etc. It also comes with WIN2K fully installed. Any issues you see with that? Terry
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[DaPi]

I my opinion (and in reverse order):

3) You have enough probs - don't add to them! A migration should be planned & tested.

2) If you use the W2K you'll have to install Oracle. If you stay with the same machine un-installing (option on install CD) and re-installing the software should be OK - my only concern is potential conflicts in the registry because the de-install does NOT clean it out . . . my bet is that it would be OK.
Note that this would probably wipe out the <ORACLE_HOME>\Network\Admin parameter files and maybe init<SID>.ora - see below.

1) The Instance is defined by the NT service - OracleService<SID> - ORADIM is used to delete and create these if you think it is neccessary. You will need the init<SID>.ora file for this and starting the db later. You are also going to need the sqlnet.ora, tsnames.ora and listener.ora thet are under <ORACLE_HOME>\Network\Admin

Are you running in ARCHIVELOG mode?

1a) If NO, then the status of Sunday's cold backup is the best you will get. It should be easy: what you need to do is restore ALL the db files (system, data, index, temp, rollback, redologs, control files) to where they came from, start the NT service and run your startup script.

1b) If YES, and you have the archived logs safely copied to another machine, then you can restore to the time of the last log switch or better - BUT it's more complicated and depends on which files of your db went west with the disks.
In this case I would backup the corrupted situation to tape ( ! yes ! ) so that when I screwed up the recovery I could have another try! (been there, done that, they don't do T-shirts)
If only data files have gone, the basic outline is to restore ONLY the corrupted/lost files, mount the db and run ALTER DATABASE RECOVER AUTOMATIC.
If you have lost redologs and/or control files - we both need to read the manual (never done it myself). DaPi - no silver bullet

 

[DaPi]

If you are not sure if you db is OK - there is a program dbv (database verify) - see chap 4 of the Backup and Recovery Guide.

GOOD LUCK DaPi - no silver bullet

 

[THoey]

Thanks DaPi. Okay, I'll address your points as you listed them.

3. Okay, as far as not upgrading to 9i. Someone had just mentioned that it might kill two birds with one stone if we upgraded at the same time. My concern was taking a cold back up of 8i and trying to load it on a 9i server. Not sure if the file format had changed, etc. I would think it would be better to go back to 8i and then migrate later.

2. If I go with the old machine, I will uninstall first, go through the registry to clean it up and then reinstall completely. If I go with the new machine, well, it will install it all.

1. With either new or old install, since I am going to completely do a new install of Oracle, I gather I need to use Oradim to create the four instances. I plan then to shutdown all four instances and copy all of the backed up files (those orginally created by Oradim and the files that I have created) over top of those that Oradim created.

1a. We are running in NOARCHIVELOG mode, but I have access to the data files that have been created since then that I can manually load.

Thanks again for your ideas. I did a search on Metalink and came up with something like this, but they don't explain it as well. Terry
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