Originally posted by: robinsguk

AIX 6.1.

I have 2 x 740s each with an AIX LPAR defined.

All storage is defined using vscsi through VIOS.

The storage is provided by V7000 and replicated from site A to site B for DR purposes.

On my LPAR in site A I have hdisk0 through to hdisk14 available.

When I test DR by:

shutdown AIX LPAR at site A

Switch the 15 LUNs in v7000 to replicate the opposite direction

Activate the DR LPAR at site B

I get a boot issue as the LPAR at site B can't locate hdisk0. I can force a reboot using SMS by scanning for the SCSI disks.

When I log in hdisk0 to hdisk14 are now defined and hdisk15 to hdisk29 have been created and are available.

I use the same procedure for IBM i LPARs and it works a dream.

My guess is that AIX is detecting different UUIDs for the replicated disks so Is creating new devices.

Is there a way to get around this?

Can I instruct AIX to detect disks by SCSI ID rather than the UUID?

thanks

Glenn

Originally posted by: dukessd

There are all sorts of problems, as you are finding, with cloning AIX in an unsupported way - other operating systems are not so 'aware' of their surroundings - and this is probably due to the nature of the way AIX has developed and all the problems and pit falls that have been encountered along the way.

AIX has developed, and is now aware of, and tries to protect its self and any data it might be connected to, from things like you are trying to accomplish because the way it is fundamentally designed and all the pit falls replication might cause.

There are many ways to accomplish the results you are looking for and there are many reasons some methods, that seem to be quite reasonable, simply will not work.

It is well documented and reasoned what is possible and safe as well as what simply will not work.

Bring up your boot disk on a new system with a different connection to different luns on a new SAN and the better part of the ODM is obsolete so just about any, or even every, device will go Defined and a new device will be configured and become Available - not a good place to be...

Start with a web search about cloning AIX, for starters:

http://www-01.ibm.com/support/docview.wss?uid=isg3T1012273

It only gets more complex when adding the VIOS layer.

Good luck.

Originally posted by: robinsguk

Thanks for this.

Looking through the documents it seems that the ghostdev function is what I need to implement,

Originally posted by: dukessd

That's a good starting point, don't forget about custom device attributes though, like setting fast fail and dynamic tracking for your fibre adapters, and a no reserve policy for the SAN luns - could be tricky without a reboot if you are hoping to boot up from the SAN...