Lost of Control File

Hi,

1. My database is up and running since morning 9 O'clock.
2. I have three disks and in the first disk I have only master
control file (i.e the first control file in the Init controlfile
list).

Ques 1. If at any cost, my first disk will crash at any time(I don't
know when it has opened) does my Database will throw any
ERROR when the database is up and runing?

Ques 2. Secondly, if I will copy the control file from the other disk
to it's original first disk, will it give any problem to open
my database?

Regards

1)Yes, if you lose a controlfile while the system is up you will receive an error.

2)Yes, if you copy a valid controlfile from another location to the primary you can restart the instance.

Regards

There is no such thing as a 'master' control file. You have at least 2 copies of the control file which are exact opies of each other

If you lost just the control file, shut the db down, copy the good control to another place so you have two copes again, add this to your init.ora file and startup.

1. Does database give error as soon as the control file get lost or
When I will try to shutdown my database later?

2. If the database will give error immediately --- the what error
shall I get?

3. And if the database will give error while shuting down my
database .. what error shall I get?

Thanks and Regards

I tried this for you.

You wont get the error immediatelty, you will get it when the DB tries to write to the control file, which wont be too long.

If the control isnt there you will get this if you shutdown

SQL> shutdown immediate
ORA-00210: cannot open the specified controlfile
ORA-00202: controlfile: '/u02/oradata/RE8/control1.ctl'
ORA-27041: unable to open file
SVR4 Error: 2: No such file or directory
Additional information: 3
SQL>



What I had to do was shutdown abort, make the changes on the OS level and restart

So, even if I will try to move my one datafile to a new location, then also I will get the error right?

Thanks

Ok, if we are just talking about control files here do this.

Get the database shutdown.

Take a copy of the GOOD control file and copy it to the location of the other control file. If that disk has gone then copy it to a different place and edit the init.ora file and put the location of the new control file in there at the same time removing the location of the old one

Quote:

---

Originally posted by newcomer
So, even if I will try to move my one datafile to a new location, then also I will get the error right?

Thanks

---

Yes, if the control file cannot be located in the place specified in the init.ora the error will occur.

Hi Jovery,

Thanks.

1 But in such case, does Oracle allow me to move the datafile to a
new location in database level?

2. Or it will fire the error while trying to update that information in control file?

Regards

Sorry you've confused me a bit here,

If you now asking if you can move a datafile while the database is up? If so the anser is yes.

If your asking can a control file be moved when the database is up the answer is no.

Regards

I am sorry!!

What I would like to know that, suppose I don't know that some thing wrong has happened in my first disk.

And I try to move a datafile of a particular tablespace to a new location ...... U said I Oracle will fire an error.... My doubt is does oracle allow me to move that file at that time or it stop me there itself?

Regards

If you are trying to move a datafile to a new location when the database is up Oracle would retain the old location until you had physically move the file via a host copy command and in your senario this is where you would get the error but it would not be an Oracle error but an OS one.

eg.

To move a datafile while the database is open:

1. Make the tablespace READ_ONLY
2. Take the tablespace offline
3. Move the datafile via the OS --> this is where your error would occur.
4. Update the file location in Oracle
5. Bring the tablespace online
6. Make the tablespace READ_WRITE

Therefore if the error occured at point 3 and the file could not be moved it would remain in it's original location and you would simple skip point 4.

HTH

So, the error will occur at point # 3, bcoz of missing the controlfile right? Not for any other constraints.

Ok, I would like to clear one more doubt ....

1. Suppose I lost all my original control files, and Backup control files.

2. I am going to create a new control file with the details of existing datafile names and size.

3. I know the name but how to get the size of those files? Will u suggest me to take it from O/S level? but sometimes oracle give error even I am taking size from O/S.

What do u suggest?

Regards

Quote:

---

Originally posted by jovery
To move a datafile while the database is open:

1. Make the tablespace READ_ONLY
2. Take the tablespace offline
3. Move the datafile via the OS --> this is where your error would occur.
4. Update the file location in Oracle
5. Bring the tablespace online
6. Make the tablespace READ_WRITE

---

Do we really need to put tablespace in READ ONLY=
And why?

It works without...