Informix Online & EMC Symmetrix BCV backup query

[B Woolley]

We are running Informix Online 7.3 and are looking to implement backups via a BCV on EMC disk. Databases are all on raw logical volumes so we'll be using Omniback to do the actual backup. I'm looking for help on the sequence of steps that we need to do, both for backups and restores. We currently use ontape do do logical log backups and database archives but I believe that we need to use onbar.

We are looking at only doing cold backups so I do not think that we need the Omniback/Informix integration?

Any help/pointers gratefully received.

Thanks,
Brian Woolley.

[Darrel Louis]

Hi,

When you want to perform a backup of a Informix Instance, you need the OBII/Informix Integration. You must install it on your Cell Server and distribute it to the Servers running Informix.

- onbar -b -L 0 # full backup, backup of the specified dbspaces
- onbar -b -w -L 0 # Whole Backup, backup of all dbspaces
- onbar -r # cold restore
- onbar -r -w # Whole restore, will recreate dbspaces.

Some documents which can be handy to read:
http://managementsoftware.hp.com/Call.asp?contexID=136&link=library

http://managementsoftware.hp.com/Uploads/443.pdf
http://managementsoftware.hp.com/Uploads/omdb401.pdf
http://managementsoftware.hp.com/Uploads/415.pdf

Good Luck

[B Woolley]

Darrel,

Thanks. I can see how this would backup the logical volumes in use by Informix but how do you get it to look at the split off BCV copies of the volumes?

Regards,
Brian.

[Steven Sim Kok Leong]

Hi,

I do not know about EMC+Informix. However, I can relate about XP256+Oracle in my environment.

Our Business Copy backup basically follows the following algorithm:

In the /opt/omni/lbin/orabkup_pre omniback pre-backup script:
1) remote login to the database server
2) shutdown the database
3) split the copies via HORCM commands
4) startup the database

An omniback filesystem backup for Oracle filesystems proceed as normal.

In the /opt/omni/lbin/orabkup_post omniback post-backup script:
1) merge and synchronise the copies via HORCM commands

Hope this helps. Regards.

Steven Sim
Brainbench MVP for Unix Admin
http://www.brainbench.com

[UNIX Admin Group_1]

Look into the command: onmode -c block
You run this, and it does a checkpoint and blocks any more activity to the disks. You then split off the bcv mirror. Because you did a checkpoint, the split copy will be consistient at the time of the checkpoint.
To re-enable disk activity, do:
onmode -c unblock
I believe there is a white paper on Informix's website about this.

[Tim Malnati]

It's really quite simple... suspend and sync the database (onmode appears to be the command to accomplish this), split off the bcv, and then unsuspend the database.

But here is an additional benefit worth considering... After the bcv is split off you can mount this volume to any machine connected to the EMC. What this means is that you can have another server actually perform the backup and eliminate the backup processing load from your production database server. This is particulary beneficial in an environment that uses a tape library where several backups from several different machines are typically stacked up. In practice this allows the backup server to fully control the overall backup activity of the library which allows it to be much more efficient.