Reinstalling VMware, keeping luns in tact

[greggap]

Hi All,

I have read some stories regarding Vmware reinializing/erasing luns even when reinstalling ESX on local disks. We have four hosts running on blades where I need to reload the OS locally on each blade. How do I make sure the luns are preserved and not touched at all during the reinstall without physically unplugging them.

Thanks,

Greg

[sbeaver]

What kind of blades? If you are using HP then HP uses CCISS for the driver so it makes it a little easier for install with the fiber installed. The best bet is to unplug the fiber or to mask the LUNS from the SAN. Also once you have installed ESX an install file called andaconda.conf is created which can be used to re-install a server based on the answers to the setup questions during the install.

Word to the wise... Before overly cautious!! Blowing up a LUN during an install with running VM's can really ruin your day and is not fun to try and recover from.

Steve Beaver

VMware Communities User Moderator

VMware vExpert 2009

====

Co-Author of "VMware ESX Essentials in the Virtual Data Center"

(ISBN:1420070274) from Auerbach

Come check out my blog: www.beaverdam.net/blog

Come follow me on twitter http://www.twitter.com/sbeaver

*Virtualization is a journey, not a project.*

[greggap]

That's exactly why I am asking, I don't want to blow up a lun.. The blades are HP BL460C G1.

Thanks,

Greg

[sbeaver]

Pratice first but with HP hardware it is alot easier because CCISS will be local drives only. I have never blown up a LUN on HP hardware. Now if you really want to get creative do a search for custom ESX install ISO where you can remove any and all reference for loading the fiber drivers during the install.

Pratice and play to get yourself comfortable with the process and use a fake LUN with data you do not care about, but again you are starting off in a good place with the HP hardware. Look for anything CCISS, those are your local disks

Steve Beaver

VMware Communities User Moderator

VMware vExpert 2009

====

Co-Author of "VMware ESX Essentials in the Virtual Data Center"

(ISBN:1420070274) from Auerbach

Come check out my blog: www.beaverdam.net/blog

Come follow me on twitter http://www.twitter.com/sbeaver

*Virtualization is a journey, not a project.*

[greggap]

Im not too worried about choosing the wrong disk to install ESX on, I was just worried it would do something to the luns without my knowledge... Can I then just readd the datastore with the existing vm's with no issues after the install?

Thanks,

Greg

[sbeaver]

Yes you can. Remove the zoning so no LUN are presented during the install and then re-zone the LUNs back after the install and you will have no problems

[greggap]

Sorry I'm kind of a SAN newbie, we didn't do anything at the switch level, how would I disable zoning before I reinstall?

[sbeaver]

Either Zoning or masking, whichever way you un-present the LUNS from the ESX server or pull the cable. Again with the CCISS as the driver as long as your careful you will not touch or mess up any of the LUNS.