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George_M
Contributor
Contributor

MSCS Clustering

Hello all,

I would like to setup a 2008 R2 cluster across two ESX 5.0 hosts. I followed the "Setup for Failover Clustering and Microsoft Cluster Service" guide and ran into some issues. To begin, I do not have vCentre and all work is being done directly via stand-alone vSphere clients - I suspect this may be the issue. In regards to the shared quorum, I confured the raw FC lun on one the first cluster node on machine #1. The guide states that you must then configure the quorum on the second cluster node by adding a disk and then selecting "use existing volume". When I do this and browse, I cannot see the datastore/volume created on the first machine. I did store the disk info to a datastore on my SAN so it can be shared between machines.

I must have missed something during the process as I cannot seem to understand how the two physical installations are sharing volume information. That is, when I specify "use existing volume" on the second ESX server, how does it know how to reference the shared datastore (where the RDM info is stored) that was created on the first server?

Any assistance would be appreciated.

Thank you.

GM

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NuggetGTR
VMware Employee
VMware Employee

When you choose use existing disk you have to choose the vmdk file which is acting as the pointer of the RDM. Just like you would add any existing disk to a virtual machine.

if you cant see the datastore of file then it sounds like the 2 esx hosts are not connected to the same storage at least not to the storage where the virtual machines are installed on,

When setting up the Quorum you would have selected rdm and then pointed it to a LUN, the it would have put a <machine name>.vmdk file in the virtual machine location (a datastore presented to ESXi host) it will display the size of the RAW LUN. this is the VMDK file you must select on the second virtual machine.

you dont require vCenter I wouldn't think as there is nothing in setting up a MSCS cluster that requires anything from vCenter. Obviously if your sharing storage it is neater to use vCenter.

________________________________________ Blog: http://virtualiseme.net.au VCDX #201 Author of Mastering vRealize Operations Manager
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George_M
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Hi Nugget,

Thanks for your reply. On the second physical machine; if I add disk and select "raw device mapping" I will see all of the LUNs that are available to the first physical machine. This means that all HBA WWNs have been properly assigned to the storage volumes and both servers can see the shared storage. During the creation of my shared volumes/LUNs, I created a 10gig volume to use as a datastore for the RDM file. During the addition of the quorum volume to the first cluster node, I instructed vSphere to store the RDM on the 10gig volume that was mapped to both physical hosts. The RDM file was created. On the second physical host when I create a hard disk and specify "use an existing virtual disk", I cannot see any datastores, specifically the one created for the RDM file on the first host, other than the ones actually created on the second physical host. I was thinking that some other step is required to have the machines share their datastore information. Is vCenter necessary for this? I do not have vCentre. If not, what am I missing?

Thanks

GM

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George_M
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I have made some progress. On the second ESX 5 server I went into the storage config and selected "rescan all". After a few seconds, the datastore created on the first ESX 5 machine appeard. I then added a second hard disk to the second cluster node and I was able to select the quorum file from the datastore. I specified SCSI1:0 as on the first node however it did not present me with the option of physical or virtual compatibility. All I could select was Mode - Independant/Persistent. Upon completion, I was presented with the error:

Incompatible device backing specified for device '0'

Any ideas?

Thanks

GM

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NuggetGTR
VMware Employee
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On the second physical machine; if I add disk and select "raw device mapping" I will see all of the LUNs that are available to the first physical machine

no on the second one you would not select raw device mapping, just exisiting disk, it will pick up if its a RDM or not.

I have made some progress. On the second ESX 5 server I went into the storage config and selected "rescan all". After a few seconds, the datastore created on the first ESX 5 machine appeard. I then added a second hard disk to the second cluster node and I was able to select the quorum file from the datastore. I specified SCSI1:0 as on the first node however it did not present me with the option of physical or virtual compatibility. All I could select was Mode - Independant/Persistent. Upon completion, I was presented with the error:

Incompatible device backing specified for device '0'

Any ideas?

have you made sure the scsi controller 1 is running as physical scsi bus sharing? this has to be enabled on both machines,

after adding the disk you have to go to the scsi contoller and enable the option, the second machine will auomatically pick up its a physcal mode RDM because all that information is in the poiter file vmdk the first machine creates

________________________________________ Blog: http://virtualiseme.net.au VCDX #201 Author of Mastering vRealize Operations Manager
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George_M
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Hi Nugget,

1)     no on the second one you would not select raw device mapping, just exisiting disk, it will pick up if its a RDM or not.

I did this to ensure that the second machine was able to see the shared disk and not for configuration purposes.

2)     have you made sure the scsi controller 1 is running as physical scsi bus sharing? this has to be enabled on both machines,after adding the disk you have to go to the scsi contoller and enable the option, the second machine will auomatically pick up its a physcal mode RDM because all that information is in the poiter file vmdk the first machine creates

I did this as well. In fact, I selected the physical while the hard drive was “adding” to the configuration. Once I exited the config, the same error was thrown.

Please see the attached screeshots:

adddisk1.png

adddisk2.png

adddiskerror.png

Thanks again for your reply.

GM

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NuggetGTR
VMware Employee
VMware Employee

I see you selected independant disk/persistant setting, I dont know if this would affect it but this is something I have never set and dont believe the doco says to set this.

also can you show the setup for the first node?

looks all fine apart from the independent disk settings.

Cheers

________________________________________ Blog: http://virtualiseme.net.au VCDX #201 Author of Mastering vRealize Operations Manager
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