[twieckow]

Hello, I have (Porbably a basic) question. I'm fairly new to AIX, and we are looking at mirroring are ORacle DB's, splitting off the mirror to do backup and then resync. Our ORacle filesystems reside on Raid 5 EMC san storage running powerpath. So, basicly, looking for commands in order to create a mirror of each VG/Filesystem, then splitting the mirror off and mounting the mirror to the same system to do backup? From what I read, can this mirror ONLY be mounted RO? COuld I in fact mount this mirror, to say startup another Oracle Instance to it ? Or is it only Read only, in order to backup from? Hope this makes sense,
Reagards Tom.

[FASherman]

What version of AIX are you using? The answer hinges on that question.

[twieckow]

Hi, Sorry I did'nt mention before 5300-03,04.
Thanks very much

[FASherman]

The command you want to use is splitvg:

splitvg -y SnapVGname -c Copy VGname

So you would enter:

# splitvg -y OraSNAPvg -c 3 OraDBvg

(this assumes you have three copies so that the VG is still mirrored after the split. Substitute -c 2 for -c 3 if you have only two copies. Also understand your DB will be at risk for the entire time the backup is being run.)

When you're done the backup, simply rejoin the volume group:

# joinvg OraSNAPvg

But remember, this is a snap volume. It does have limitations. If you need more flexibility you could try something like this:

# splitvg -y OraSNAPvg -c 3 -i OraDBvg

(The -i means that the split is permanent)

Record the hdisks in OraSNAPvg, vary it off and export it. Now type:

# recreatevg -y OraCopyvg list of hdisks

Now you have a regular volume group with no limitations. You can run it as another instance or, if SAN based, you can export/import it on another server/LPAR. Its a fast way to copy production databases to development servers/LPARs.

Just be sure to quiesce the database before issuing the snapvg. Also make sure there are no stale logical volumes.

[twieckow]

Fred, Thanks very much for the advise.
I will give this a try. Appreciate the feedback.
Tom

[FASherman]

Let me know how it works out.