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XP12000 CV CLI -- Cannot "create lun" with LUN No. greater than 255 (FF)

Alzhy
Honored Contributor

XP12000 CV CLI -- Cannot "create lun" with LUN No. greater than 255 (FF)

Has anyone seen this problem yet? I used to be able to prior to our CommandView 2.0 getting re-installed.



CV_CLI 30015 (R/W)> create lun 3b:4b,fhp007b,3f1,0,31

Sending Request to CV server ...


30015 : The server has latest data.

Error: 3f1 The specified LUN id is invalid

CV_CLI 30015 (R/W)> create lun 3b:4b,fhp007b,f1,0,31
Sending Request to CV server …
30015 : The server has latest data.
Create LUN operation is successful.
Hakuna Matata.
6 REPLIES
ESC Team
Advisor

Re: XP12000 CV CLI -- Cannot "create lun" with LUN No. greater than 255 (FF)


Hello Nelson,

The Commandview XP V2.0 CLI Reference Manual says that the LUN ID parameter of the "create lun" command has a valid value range of 0-255 and must be specified in hex (ie: x'00' to x'FF').

What has led you to believe that LUN values greater than x'FF' are allowed? Commandview XP 1.8 has the same valid value range for this parameter.

Regards, Maurice Clark.
ESC Team
Alzhy
Honored Contributor

Re: XP12000 CV CLI -- Cannot "create lun" with LUN No. greater than 255 (FF)

Hmm.. I must have been done it via the GUI then. Who knows?

Anyways - if I am going to do presentations with LUN numbers greater than 255 - I have no other option then but to do the GUI? I am sure we will not be alone to have this need but will this ever be fixed/enhanced?
Hakuna Matata.
ESC Team
Advisor

Re: XP12000 CV CLI -- Cannot "create lun" with LUN No. greater than 255 (FF)

Hello Nelson,

I'm not sure...good question though, let me
see if I can find out.

Maurice Clark.
ESC Team
Vincent Fleming
Honored Contributor

Re: XP12000 CV CLI -- Cannot "create lun" with LUN No. greater than 255 (FF)

Last I saw, the FC/SCSI protocol specification allows only a single byte for LUN number; hence the limitation of 255 LUNs. These standards are very slow to change, because it would cause a change in the size of the data structure sent between the array and the host for every I/O operation.

It would be ugly to change the spec - every vendor would need to change their implementation - OS vendors, switch vendors, array vendors, software vendors, etc.

There are several ways you can circumvent this limitation, though, such as using more ports on the XP and/or more HBAs in your server - you can put 2 HBAs from the same server on the same port (as far as the XP is concerned, diffferent WWN's on the cards make them different - just put them in different host groups.)

So, if you had 4 HBAs in your server, 2 per fabric, you could have 2 HBAs get different sets of LUNs from the same XP port (ie: CL1-A), if you put the 2 HBAs in their own Host Groups.

Cheers,

Vince
No matter where you go, there you are.
Alzhy
Honored Contributor

Re: XP12000 CV CLI -- Cannot "create lun" with LUN No. greater than 255 (FF)

Vincent.. The XP indeed allows for mapping LDEVs to have LUN numbers greater than 255.. the virtual bus is simply increased every 128 LUNs..

I am just wondering why the GUI will allow this whilst the CV CLI is only restricted to no more than 255.
Hakuna Matata.
Vincent Fleming
Honored Contributor

Re: XP12000 CV CLI -- Cannot "create lun" with LUN No. greater than 255 (FF)

I guess my age is starting to show... ;-)

I found in the docs that the XP itself will present LUNs numbered from 0 to 1023. You are correct.

The limitation you see is no doubt a CLI limitation.

Have you opened a case with Support?
No matter where you go, there you are.