Best LVM config with JBOD 2405 and Oracle 8i

[Dan Hardison]

We have just acquired a new rp5470 running 11.11 . It's principal job will be to run an Oracle 8i database which will be 200Gb-300Gb in size. The disk system consists of 3 - JBOD DS2405 enclosures with a total of 32 - 18Gb disks. The DS2405s are connected via dual 2Gb fibre channel controllers.

What is my best LVM configuration with Oracle 8i? Use straight mirroring? Mirroring with striping? PVLINKing? Suggestions on tuning or configuration checks much appreciated.

TIA,Dan

[Eugeny Brychkov]

Dan,
acquire VA7410 main controller enclosure and most of these problems will dissapear. Only you'll need is to configure SAN correctly (may be done by HP engineers)
Eugeny

[Dan Hardison]

Eugeny,
I'd love to be able to do that, but the budget is shot. Any suggestions on working with what I already have?
Thanks,
Dan

[Sridhar Bhaskarla · Accepted solution]

Hi Dan,

If you can, I would suggest to go with VxVM that offers a lot many features that LVM does not. Mainly it does Raid0+1 whicn would be what you may want to do.

You can still do mirroring with striping using LVM. BUt, it is going to be only extent level striping which does not seem to offer much performance gain.

If VxVM is not an option, I would try to balance between availability and performance.

If you want availability with default performance, you can go with extent level striping/mirroring. You will be safe and I would suggest this approach. Make sure every other disk is on the alternate path to load balance the controllers. You will need to create PVGs to have extent based stripe/mirror. The command you would use is

lvcreate -D y -s g -m 1 -L size /dev/vg??lv??


If performance is paramount for you then go for LVM striping with a set of 4 disks. It will offer good performance. Also, try to allocate every alternate disk on the other controller so that both the controllers are load balanced. However, if any of the disks is lost, you will need to restore the db from the backups and it will be back to the stage when it was backed up.

-Sri

[Patrick Wallek]

Dan,

I would go with mirroring and distributed striping on these. Do a 'man lvcreate' for details on distributed striping (the '-D' option to lvcreate). Note that distributed striping WILL work with mirroring whereas regular striping (the '-i' and '-I' options) will NOT work with mirroring.

Patrick

[Dan Hardison]

Sridhar,

The system currently has Base-VxVM installed. Does the "base" product support RAID0+1 as you suggested or would I need to purchase the "advanced" product?

Dan

[Sridhar Bhaskarla]

Dan,

Unfortunately Base-VxVm does not provide the features of mirroring.
You will need to purchase the advanced product I believe B9116AA to get these features in addtion to DMP. Look at the following document for more details on administering VxVm.

http://docs.hp.com/hpux/onlinedocs/B7961-90025/B7961-90025.html

-Sri

[Dan Hardison]

Thanks guys. Looks like I'll go with the extent level striping/mirroring option.

Dan