Mirroring database and application disks in HP-UX

[Bachur]

Hi,

What is the method of mirroring all my database and application disks.

I have eight disks and I have mirrored the boot disk. Now I have 6 more disks, out of these 2 are database disks and 1 application disk. My OS is HPUX 11iv2 and I am having a two node cluster setup. I am planning to implement VxVM for the database and application data.

How can I mirror these application and databse disks so that my system would be running smoothly in case of disk failure?

Please note I am planning to implement software mirroring.

Please let me know the steps if possible.

Regards,
Bachur

[Steven E. Protter]

Shalom Bachur,

You don't say a lot about your disks. If its in a hardware array that is configurable, the best way to mirror is hardware mirroring. Configure your disk to present the hp-ux server with raid 1 mirror copy.

If that is not possible, there is an add in product for software mirroring called mirror-ux. I don't remember if it works with VxVM, though I can't see why not. VxVM is a Veritas product and the rootvg can be mirrored at no extra charge. There is software from Verits to handle mirroring if mirror-ux does not do the trick.

SEP

[Ninad_1]

Since you have decided to go for software mirroring and use VxVM here are the steps

1. Create 2 disk groups - 1 for data and other for application using 4 and 2 disks respectively.
When selecting the disks make sure that half of the disks in a disk group should be on one SCSI path and remaining on seperate. for this simplest way to determine is your controller no. cxtydz -
e.g. c1t1d0 , c1t2d0 , c2t1d0 , c2t2d0 - add these disks in data dg (so that you will use 2 c1 disks for original volumes and the 2 c2 disks for mirrored volumes)
2. Create the required volumes on the first set of disks.
e.g. create the required volumes on c1 disks.
vxassist -g datadg make vol1 1000m disk1 (assuming disk1 is refering to c1... disk)
3. Mirror the volumes to use the second disks for mirroring.
vxassist -g datadg mirror lvol1 disk3 (assuming disk3 refers to c2....)

Regards,
Ninad

[Albert_31]

Hello Bachur,

The base VxVM product that comes default with HPUX os, supports mirroring only for the rootdg.

Which I guess will not suffice since you would like to have the database and application in two different dg's being a cluster setup. So you have to purchase the license or the full vxvm product to have raid-1 capability for dg's other than rootdg.

Else you could have database or application in LVM maintain a mirror using Mirror-UX and the second one in VXVM, use the rootdg for the FS and have mirroring enabled.

so depending on what you would like to take..let us know

regards

Albert

[Bachur]

Hi Albert,

I wanted to know what Volume manager should I use for Oracle database?

Should I use LVM or VxVM for database?


Regards,
Bachur

[Albert_31]

Hello Bachur,

Actually it depends on what type of storage device being used. If the storage is high end, then the volume manager is not so important since the storage will take care of data redundancy etc. But if your storage is a simple one, then the volume managers role is highlighted and important.

Only mirroring, both are good so you decide which you are more comfortable with.

If you go for VxVM, you have to buy the full product or teh license i guess, whereas with LVM you already have the product with you.

Full Product of VxVM has features like hot relocation which LVM also has but not widely used I think..

multipathing - LVM uses Native PV links and has no load balancing features, whereas full version of VxVM has the multipathing features if the storage support it and if there is teh ASL (array support library) for the storage on VxVM.

This is all i could get off the mind now and they may be more.. which our colleagues in the forum might put in...

Regards

Albert