How to move to a new array when using boot from SAN


Image: EMC

Last week I helped a company move from its old EMC CX4 array to a new EMC VNX. The company's production environment was running on various Cisco UCS blades with VMware vSphere 5.1 as the hypervisor.

Migrating to a new array can be daunting, but with technology like VMware's storage vMotion it's become a lot easier. However, if you're booting your VMware servers from a LUN on the SAN, it can add a bit of complexity.


The environment pre-migration



The step-by-step process

  3. Put the host in the storage group with the boot LUN. Everything was already zoned in our environment, because we were already presenting LUNs to the hosts. If you're using fibre channel, you'll need to do some zoning for the host to show up in the array.
  5. Remove all zoning/paths to the old array, so you don't get confused about which boot LUN you're going to use. This step isn't absolutely necessary, but it makes it cleaner.
    • a. Add the SAN boot primary and secondary information.
    • b. Get the World Wide Port Number (WWPN) from the storage array by looking at the host initiator's properties -- it will be the last half of the World Wide Number (WWN) or unique ID they have listed. The first half is the WWN of the array, which you can find under the hardware system properties (applies to EMC VNX).
  8. Click the server you're working on in UCSM.
  9. Go to the Boot Order tab.
  11. Add the ISO image to the Virtual Media from the KVM console (if you're installing from an ISO).
  12. Reboot the server and press F6 to specify how to boot, and you should see both a vDVD option and the LUN (e.g., DGC naa.xxxxxxxxxxxxx) if you've done all the previous steps correctly. If you don't see the boot LUN, make sure your zoning and boot policy are correct.
  13. Choose to boot from the vDVD option, and you should see the ESXi installer. Make sure you're using the Cisco custom ESXi image to get all the drivers you need.
  14. Eventually you'll get to a screen where you can specify that you want to install the ESXi OS to the boot LUN.
  15. If you'd like to add the servers back to the service profile template, then change the template to have the new boot policy. If this is an updating template, it will automatically update any service profiles that are bound to it, so you may wish to do this during a maintenance period (if you're doing all of it during planned downtime, then you don't have to bother unbinding the templates -- you can just change the service profile template in the beginning).

Completing the configuration

If everything in the step-by-step process goes well, you will need to reconfigure your management network and other network settings since this is a fresh install. You can add the host back into your VMware cluster. You'll need to manually connect it since VMware sees it as a new host with a different security fingerprint, as well as reconfigure your vSwitches if you're not using the distributed vSwitch.

