Re: How to move raw datafiles?

Hi All,

 I was going to suggest the same thing (using dd). One word of caution. If you use a large blocksize, you could miss the last few oracle blocks if the raw disk is not a multiple of the large blocksize. For this, I would use a 1024 blocksize to be safe. I used to work with Informix where we always used raw and we did encounter this issue.

 You probably did this too, but we always used symbolic links to the rlvols to make life easier. It seems obvious to do this, but I have seen many DB's where the datafiles/chunks are named /dev/vgxx/rlvolxx; dumb! We always create a dir /var/opt/oracle/rdisk and then create links called: DBNAME_TSNAME_(DF Number).dbf which is a link to the /dev/vgxx/rlvolxx device file.

 Good luck!

 If this posting has been useful, return the favor by visiting http://dbamon.com .

Bill

--
Bill Border
bb22_at_uswest.net
Low-Cost, UX-Based Oracle/Informix Monitor: http://dbamon.com




Erwin Dondorp wrote in message <39F34FCC.4C7ED86_at_dondorp.com>...


>mr_potato_head_at_my-deja.com wrote:

>> Can someone explain to me in detail how to move my raw datafiles?

>

>Rule #1: Make sure the disk sizes are equal!

>

>The procedure is the same as for moving database files in the

>filesystem.

>Use all the usual "ALTER DATABASE" commands.

>But instead of the "mv" or "cp" command use the "dd" command.

>

>e.g.:

> dd if=/dev/sourcedisk of=/dev/destdisk bs=1024000

>

>With the explicit block size ("bs=" clause) things should be faster

>and you will be able to verify the amount of bytes transferred.

>The output of "dd" will be something like

> 1000+1 blocks read

> 1000+1 blocks written

>The numbers indicate the number of full+partial block transfers.

>See also "man dd".

>

> Erwin