Destroy LUN when reattaching server - What can cause it?

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I'm playing in the lab with a VNX 5300, and I'm going through a test scenario of my fiber attached Windows server blowing up and needing a rebuild. The basic idea is to rebuild the windows box, reconnect the SAN, and NOT lose data.

The specs are a Windows 2008 server connected via Fiber(direct, no switches) with (2) HBAs and MPIO.

The question is, in this type of scenario, what can cause the LUN to get destroyed(lose data) or is there best practice for reattaching a rebuilt server(or connecting a new server) to a SAN?

Thanks in advance,

Jon

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dynamox
6 Gallium

Re: Destroy LUN when reattaching server - What can cause it?

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If there is not corruption on the LUN itself where metadata got lost, you should be able to rebuild the server and re-attach the LUN. It gets funky if you are using dynamic partitions but you should still be able to import it. If you are using basic partition then once you rebuild the server it’s just a matter of presenting the LUN and assigning a drive letter ( you might need to bring it online if it’s Win2k8/12)

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dynamox
6 Gallium

Re: Destroy LUN when reattaching server - What can cause it?

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If there is not corruption on the LUN itself where metadata got lost, you should be able to rebuild the server and re-attach the LUN. It gets funky if you are using dynamic partitions but you should still be able to import it. If you are using basic partition then once you rebuild the server it’s just a matter of presenting the LUN and assigning a drive letter ( you might need to bring it online if it’s Win2k8/12)

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LeeGoodwin
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Re: Destroy LUN when reattaching server - What can cause it?

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I think as long as meta data is intact ok

If you create a LUN and loose it there could be a reserve on that volume if you try to connect via a different mount point it could cause issues in rare cases i have seen in the past.Some PP if used with clustering will complain

Windows should be up the volume signature

But standalone couple of paths LUN should be fine

Re: Destroy LUN when reattaching server - What can cause it?

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Thanks, that answers that. Basically it looks like you have to really mess up to wipe the data out.

I did manage to do it once in the lab. I didn't realize the HP smartstart could access the lun, and I did an 'erase all disks' while the fiber was still connected. That did it....

Thanks for the quick responses!

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dynamox
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Re: Destroy LUN when reattaching server - What can cause it?

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ha..interesting, i am surprised SmartStart would touch any partitions unless they were on a supported controller. A lot of disk cloning utilities like Acronis can load qlogic/emulex drivers and give you full access to SAN attached storage ..now we need to add SmartStart to that list

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