AndyTipton
Contributor
Contributor

Can't VMotion due to SAN config problem

Added a new ESX3 host to my cluster and configured for DRS & HA but migrations are failing. Reason I believe is because this host is unable to see one particular SAN datastore that the others can see and I can't work out why.

I've been all through my SAN zoning and it's identical to the other servers. It can see 2 of the 3 stores but for some reason can't see the other one.

Anyone had this problem before?

Andy

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8 Replies
esiebert7625
Immortal
Immortal

Did you do a Rescan of LUNS and VMFS volumes in Virtual Center? Most of the time it is a zoning problem or a presentation problem with the LUN numbers. Each ESX server has to see the same LUN numbers that the others see.

Here's similar threads...

http://www.vmware.com/community/thread.jspa?messageID=498643񹯓;

http://www.vmware.com/community/thread.jspa?messageID=451973ñ®–…;

Also check out the SAN config guide...

http://www.vmware.com/pdf/vi3_esx_san_cfg.pdf

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esiebert7625
Immortal
Immortal

Also check you Configuration, Advanced Settings, Disk on that Server to see if you have a Disk.MaskLuns or Disk.MaxLun set.

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Mayur_Patel
Enthusiast
Enthusiast

Also, you may have an issue where the new host thinks that that 3rd LUN is a snap lun. I'm having that problem right now.

Anyway, if you go to Configuration, Advanced Settings, LVM and change LVM.DisallowSnapshotLUN from 1 to 0, your host may see this lun.

It is not recommended that you leave this setting at 1, but until you can figure out why ESX thinks that this LUN is a snapshot, you may have to.

Mayur

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Mayur_Patel
Enthusiast
Enthusiast

update: We figured out our problem, we did not have all of the LUNs matched an the hosts. Take a look at your LUN numbers.

Mayur

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AndyTipton
Contributor
Contributor

Thanks for all your suggestions guys. I tried each one but nothing changed. However, I also noticed that a second server that I was preparing to add into my cluster also has the same problem - can't see the 3rd datastore.

I checked all the SAN LUN's and they are 100% identical amongst each ESX host. It just doens't make any sense.

I'll let you all know if I figure it out.

Andy.

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sepso
Enthusiast
Enthusiast

Hi

Message was edited by:

sepso

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sbohnengel
VMware Employee
VMware Employee

Hi Andy,

if you assume that the LUNs cannot be seen by all 4 cluster members, It would make sense to cross check that.

SSH to all three servers and see whether you can access the VMFS volumes

cd /vmfs/volumes/ then you will see the volume

Stephan

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regis
Contributor
Contributor

Hi

juste litle question about LVM.DisallowSnapshotLUN

With mixed configuration ;

ESX see "snapshoted lun or mirroring lun" and "normal" lun

It is not recommended to leave this setting at 1 or ZERO ?

1 is by default but for see mirrored lun we set to 0 and rescan san ...

what's better situation ? many thanks .

Régis

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