RAW Device Backup

[R.MAHENDRAN]

We are having RAW Device installtion of ORACLE 8.0.4. data files. We are using DD for cold backup of datafiles.

Is it ok to take DD of RAW device into a mounted files system with sepcified name ?

Example :

dd if=/dev/vg03/pro1.data1.dbf of=/oracle/cold/data1.dbf

If so, what about restoration ? Is the following method is ok ?
dd if=/oracle/cold/data1.dbf of=/dev/vg03/pro1.data1.dbf

2. Can we take TAR backup of all files created by the above DD comands in mounted file system, i.e.,

tar -cv /pro1backup/cold/*

Will it work properly. Is anyone using the said method ?


Thanx

With Rgds
RMAHA

[Andy Monks]

dd is fine. I would recommend, using the 'bs' option. Maybe 'bs=64k' or higher. It should speed things up.

You might want to look at something like HP's Omniback. It can backup filesystems and raw devices to the same tape etc. It's a very good tools for such things. That way, you won't have to dd the raw data to filesystems and then back it up.

[Andreas Voss]

Hi,

sounds to me a little bit strange.
If you have a raw device ie. /dev/vg01/lvol1
then you don't have any files on it - raw devices are used in full capacity without any filesystem structure.
So dd would be the best to backup but with the raw device file ie:
dd if=/dev/vg01/rlovol1 of= bs=64k
If you have a filesystem on it and mounted dd is not a good choice. A tar backup is the better thing but remember to shut down your oracle application before backup.
Of course when you stop oracle and umount the filesystem you could do a dd but i think this is not a good idea.

Regards

Andrew

[R.MAHENDRAN]

Thanks for every One.

This worked!!!!,

We created dummy tablespace with a raw
datafile & we took the dd backup on
mounted file system,& tar backup of the
same taken.

Then we removed the raw filesystem & recreated,from the tape the dd file restored
back to the mounted directory,& through
dd copied back as the original raw datafile.


Database came up with out any table loss.

Thanks & Regards
R.Mahendran.