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Boot from LUN(s) question

tinhnho123
Level 2
Level 2

Hi Guys,

 

Yesterday, I added a HP server (no local disk installed) with 2 x CNA adapters to my current network (attachment). I connected each CNA adapter to each FEX in the diagram and I then powered the server up. During the boot, I entered to the QLogic Fast!Util to make sure both CNA adapters are enabled and see the LUNs then install the Windows. During the installation, the Windows see 2 drives (LUNs) but it says one online and the other one is offline. I thought the offline drive was misconfigured, I uplugged the cable of the working one and left the offline one connected then reboot the server, after that the Windows OS see the offline one is now online (note: the other one is unplugged and Windows couldn't see it)

 

Both LUNs were created with 100GB each and my goal was trying to install the OS on a server with dual-home connections if one SAN failed the other SAN still gives me the LUN. Any ideas?

 

Thanks.

5 Replies 5

richbarb
Cisco Employee
Cisco Employee

Hi there,

At the first moment don't take a lot attention about what the Windows shows up (quantity LUNs, status) before you configure the MPIO feature. That's can be confusing, since the Windows can't recognize well the LUN in all path to access it.

For you take high-availability to access the LUN though, you must install the MPIO feature on the windows, and then provide the both paths (2 VSANs) from the server to the storage. Doing this, you can disconnect anything from one side and the server should continue accessing the LUN by the other side of your network.

 

About connect both CNAs at the same time to perform boot from SAN, I not sure whether this scenario is supported, you should check in the CNA/Server vendor support.

 

You also said that you created two LUNs for the boot server? maybe I understood wrong, but keep in mind that only one can be used for boot, the storage must hand over access to the same LUN through both VSANs.

Richard.

It's a long term tradition W2003, W2008, W2012, that during installation, only one path to the lun should be available (for the reason Richard mentioned above); see eg.

http://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/os-install-guides/windows/b_B-Series_Windows_Install/BSERIES-WINDOWS_chapter_011.html#t_sanbootinstallation

Before You Begin

 

Thanks wdey for the links, I'll check them out.

Hi Richard,

>For you take high-availability to access the LUN though, you must install the MPIO feature on the windows, and >then provide the both paths (2 VSANs) from the server to the storage. Doing this, you can disconnect anything >from one side and the server should continue accessing the LUN by the other side of your network.

Thanks for the suggestion. I installed MPIO on windows (Windows is installed on the LUN) and provide both paths from server to LUN storage. It works everytime when i unplug one side, the server reboots then come back with the other side as you stated earlier. Does it have to reboot then come back when one link is broken?

 

>About connect both CNAs at the same time to perform boot from SAN, I not sure whether this scenario is >supported, you should check in the CNA/Server vendor support.

Please forget this one.

 

>You also said that you created two LUNs for the boot server? maybe I understood wrong, but keep in mind that >only one can be used for boot, the storage must hand over access to the same LUN through both VSANs.

Actually only 1 LUN but 2 paths.

Another question, how do I assign my ethernet IP address to these CNA adapter (Qlogic adapter)?

Thanks a lot for your helps. 

 

 

 

>>>>Another question, how do I assign my ethernet IP address to these CNA adapter (Qlogic adapter)?

Which version of Windows ? W2012 R2 or W2008 R2 ?

Anyway, you need to configure NIC teaming (which is available embedded with W2012, and for W2008 R2, you have to get the NIC teaming driver from the I/O adaptor vendor)

Finally you would assign an IP address to this logical NIC teaming interface.

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