topic Re: connection between SAN and the server in Operating System - HP-UX

connection between SAN and the server

masood bt — Tue, 24 Feb 2009 15:59:06 GMT

Hi.
The following are the points which I assume are correct.
A hp unix sys admin gets WWN numbers by fcmsutil command and provides it to the storage team
then he asks for the LUNS to be allocated to his server
the storage team maps the WWN numbers with the LUNS
the the server can see the LUNS when ioscan command is run

now my questions are:
suppose if the storage team assigns four LUNS then the server has to see those LUNS through four different hardware paths.

suppose the server is a vpar in a superdome and it has a PCI slot.. that means this PCI slot is letting thorugh those four h/w paths?
can someone explain me these basic fundamentals?

thx for reading

Re: connection between SAN and the server

Torsten. — Tue, 24 Feb 2009 16:14:24 GMT

It really depends on type of storage and connection.

usually you see

server slot a - switch - array port a

server slot b - switch - array port b

===> you see the LUN 2 times.

witch more array controllers and/or HBAs you see much more.

Re: connection between SAN and the server

TTr — Tue, 24 Feb 2009 16:23:39 GMT

> that means this PCI slot is letting thorugh those four h/w paths?

What exactly are you asking or what are you trying to clarify? The zoning in the fibre switches may result in multiple hardware paths as well. The fact is that in most cases many of these paths are superfluous and during a failure they all disappear at the same time. The basic fundamental configuration allows for two physical connections as Torsten mentioned and those are enough for redundancy.
You should ask the SAN team for details on your server's SAN config.

Re: connection between SAN and the server

masood bt — Tue, 24 Feb 2009 16:53:39 GMT

Now my actual question:
In an n par I have two Vpars
One vpar is installed. Another one just created but not yet installed with an OS.
Now I need to boot this second vPar through a LUN.
I donot know how to boot a Vpar through a LUN
How should I see the the LUN hardware paths from a vPar

Re: connection between SAN and the server

Torsten. — Tue, 24 Feb 2009 16:56:29 GMT

If you say

... to boot a vpar from a LUN ...

does it mean you have an OS already installed on this LUN?

Re: connection between SAN and the server

masood bt — Tue, 24 Feb 2009 17:06:27 GMT

okay. I will correct myself here.
I have an ignite golden image. I will be using this image to boot the newly created Vpar.
I have three LUNS.
I want to use one LUN as boot disk and other two as normal disks.

complications:
I have only one hardware path for a LUN available with me.
I have other two LUNS but I do not have their hardware paths.

I also want to know how do I know the hardware paths of the other two LUNS so that I can see these two LUNS from my new Vpar

thx

Re: connection between SAN and the server

Torsten. — Tue, 24 Feb 2009 17:13:20 GMT

Boot the new vpar from the golden image and enter the interactive installer.

In the H/W scan details you will find all available disks/LUNs.

If you cannot find them, let your storage team check array and switch.