Tuesday, March 19, 2013

Configuring Boot from SAN on EMC VNX for VMware vSphere 5.0

Configuring boot from SAN on an EMC VNX is fairly straight forward, but there are some little configuration changes that need to be applied.

The assumptions to the environment are:
  1. 4 HBAs per host, 2 will be used for the SAN boot while 2 will be used for datastore access
  2. All hosts will boot from LUN ID 0 (common use case when using UCS templates)

Note:  Fiber channel zoning is not within the scope of this post.


The first step to configuring boot from SAN on the EMC VNX is to register the initiators and create the host entries. If no zoning has been done yet, go ahead and zone the HBAs that will be used for SAN boot with both storage processors (SPs). Once that is done, restart the hosts and they should log in to the fabric and the VNX.

Open Unisphere and then go to Hosts -> Initiators and you should see the unregistered HBAs that are logged into the system. Next, the initiator records have to be created. In my environment, I will need to create a total of 4 records as there are 4 paths to each host (2 HBAs and 2 SP ports).


The WWN in this case is a combination of the WWNN and the WWPN. In this example, the WWNN is 20:00:00:25:B5:FF:00:17 and the WWPN is 20:00:00:25:B5:0A:00:1A. Select and/or enter the other fields. Please note that the IP address of the host does not matter for the SAN boot HBAs. Here are all 4 initiator records I had to create:

Record 1
WWN/IQN: 20:00:00:25:B5:FF:00:17:20:00:00:25:B5:0A:00:1A
SP Port: A-0
Initiator Type: CLARiion/VNX
Failover Mode: Active-Active mode (ALUA)
New Host: esxi07_boot, 169.254.1.1

Record 2
WWN/IQN: 20:00:00:25:B5:FF:00:17:20:00:00:25:B5:0A:00:1A
SP Port: B-0
Initiator Type: CLARiion/VNX
Failover Mode: Active-Active mode (ALUA)
New Host: Existing host, esxi07_boot

Record 3
WWN/IQN: 20:00:00:25:B5:FF:00:17:20:00:00:25:B5:0B:00:1A
SP Port: A-1
Initiator Type: CLARiion/VNX
Failover Mode: Active-Active mode (ALUA)
New Host: esxi07_boot, 169.254.1.1

Record 4
WWN/IQN: 20:00:00:25:B5:FF:00:17:20:00:00:25:B5:0B:00:1A
SP Port: B-1
Initiator Type: CLARiion/VNX
Failover Mode: Active-Active mode (ALUA)
New Host: Existing host, esxi07_boot


Once the initiator records are created and registered, a separate storage group for each host needs to be created. The reason behind this is that each storage group can only have one LUN ID 0, hence the need for multiple storage groups. Also, it is more secure with multiple storage groups (each with only 1 host member) as each host can be masked exclusively to its own boot LUN.

In order to create the storage groups go to Hosts -> Storage groups. Press create and give it a name.


Click OK then add the host to that specific storage group. Next add the LUN under storage group properties and ensure that you change the "Host LUN ID" to 0.


Note: You will not have the option to change the "Host LUN ID" if the LUN is already in the Storage Group. You will need to first remove the LUN from the storage group and then re-add it into the storage group.

This concludes the steps required to configure boot from SAN on an EMC VNX. However, there are a few additional steps. Once vSphere is installed, go into the Host -> Configurations -> Advanced Settings -> Disk and set the "Disk.EnableNaviReg" setting to 0. Once this is done, you can then zone and configure the HBAs for datastore access. If this setting is not changed to 0, the VNX will merge the 2 storage groups together for each ESXi host.


2 comments:

  1. Is this being demonstrated on a VCE? The OUI (00-25-b5) is Cisco:

    dig -t txt 0025b5.oui.old.nu
    ;; ANSWER SECTION:
    0025b5.oui.old.nu. 86345 IN TXT "CISCO SYSTEMS, INC."

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  2. Thanks so much John... what saved me is the "set the "Disk.EnableNaviReg" setting to 0."

    ReplyDelete