Lun numbering from different sans and enclosures

[mjpoz]

HI,

I have been searching for this for awhile and cant find an answer. Just looking for some clarity please. I have a small environment, 6 hosts with 2 different sans. One hitachi san and one Hp P200 iscsi san. The Hitachi san already existed in the enviroment and is using luns 0-7 for its disks.When I added in the Hp san i made sure my luns were numbered after the HDS, so I have 2 new luns 10 and 11 witht he new datastores on it. Only thing is when i added int he hp it also auto added in 2 lun 0 for the hp enclosure.

pic here

Is this going to cause a issue? Can I remove this or hide it so it wont cause any problems?

I have looked in the HP SMU but cant find anywhere that the enclosure lun can be chnaged. As it is a lun for the enclosure I was not sure if it would cause probelms with the disk lun. Or am I completely confused.

Thanks

Mal

[a_p_]

There's no need to use different LUN-IDs for the two storage systems. You can have the same LUN numbers on different targets (T0, T2) without issues.

André

[kastlr · Accepted solution]

Hi Mal,

some storage arrays do present the enclosure to an attached host when the LUN ID 0 isn't configured.

I'm not familiar with HP, but I would bet that when you reconfigure your HP array to use LUN ID 0 and 1 the enclosure will disapear.

And Andre is absolutly right, you could use LUN ID 0 multiple times when you're connected to multiple targets.

All you should keep in mind is that a LUN ID should be used consistently for all ESX hosts accessing that LUN.

And if you're using multiple pathes to the same array, you should use consistent LUN ID on each storage port (Target).

Hope this helps,

Ralf

[Josh26]

Hi,

The HP P2000 will always present LUN0 as part of its management.

This is not configurable on the SAN, your best bet to get rid of it is with a custome MASK_PATH rule.

Edit: That would only be a visual "fix"

[kastlr]

Hi Josh,

does it mean you can't configure a LUN0 with the HP P2000 array???

To be honest, I can't believe this.

But as I said, I'm not familiar with HP arrays.

Regards

Ralf

[mcowger]

Many low end arrays reserve LUN 0 (non configurage) for an in-band management device (SES device).

[mcowger]

This wont cause any issues.

[Josh26]

Ghost wrote:

Hi Josh,

does it mean you can't configure a LUN0 with the HP P2000 array???

To be honest, I can't believe this.

Regards

Ralf

It's exactly like mcgower said in terms of configuration.

What's the problem?  It's not like you don't have 254 other LUN numbers you can use.