Re: Reorganizing a database that has raw partions

Brad Odland wrote in message <347C6154.B0A6774A_at_cpm.com>...
>I recently inhereted a database (Oracle Server 7.3.2) that was intially
>set up with the data files on raw AIX 4.2 partitions. We are now at the
>point where we must reorganize the tablespaces to distribute I/O load. I
>am not familiar with raw partitions and would like some advice on how
>remove the data from these raw devices and place them back in journaled
>file systems. During this time we will also be restructering the
>tablespaces for performence reasons. (We realize the error of our ways
>now......)

For all intends and purposes, raw and cooked devices are handles exactly the same way by Oracle. A device name for the raw slice will ecist in your /etc/dev/ directory in Unix. In our case we have two device names for each raw slice, a binary device and a character device (the one used for Oracle datafiles) - I would think it would be the same on your system.

To load balance i/o on raw devices, you can use the dd command to move data from one raw slice to another in order to spread data from one disk array to another. And if you have a decent machine (nudge, nudge, wink, wink), down the machine, pull the disks and reshuffle them (irrespective of where the corresponding striped sets or mirrors are) and bring it up again - without touching a single Oracle configuration file. :-)

>Our plan is to export all populated tables drop all others. reomove the
>current instance and abandon it. Recover the disks used by the raw
>devices and with a new instance rebuild the database correctly with the
>proper I/O load balance by creating Volume Groups for each datafile
>contained in a particualr tablespace. Does this sound feasable or is
>there a better way?

Why not stay with raw devices? There are advantages to using raw devices, and performance is one of them (the downside is that you need solid Unix skills to support raw devices). However, if you want to do away with the raw devices and go to cooked files, I think that your idea of an export is the safest.

>Identifying what pysical partitions are associated to what raw device on
>what pysical volume (disk).

There must be a command to configure, list, rename raw devices. On our system it's called vdconfig (virtual device configuration).

>We are thinking of upgrading to Oracle 8 shortly after? or During? the
>restructuring. I would assume after would be the logical choice.

Yeah probably - one of the migration methods is to do an export of your 7.x database, install 8 and then import it into 8. Only thing I think is that this must be a full database export? The Oracle 8 docs has a special chapter on migrating your 7.x databases. Probably the best place to look.

Hope your migration is painless... :-)

regards,
Billy Received on Fri Nov 28 1997 - 00:00:00 CST