question on datastore mapping to multiple LUNs

sarbjit — Thu, 05 Jun 2025 06:49:48 GMT

IHAC where we are using snapmirror to migrate few LUNs (VMFSdatastores) from SATA to FC disks. We are planning for the final cutover andhave the few questions that I wish to clarify :

High Level Plan :

1)Shutdown the application and power off all the VMs

2)Unmount/remove the existing VMFS datastores.

3)Unmap the old LUNs from storage and do a final snapmirrorupdate to replicate the changes and ensure snapmirror goes to a idle state

4)Change the LUN serial number of the new LUNs to match theserial of the old LUNs

5)Map the LUNs at the same LUN id to the ESX hosts as theearlier LUN id’s

6)Rescan all HBA’s on the ESX host and see if the datastorecomes online.

Question :

Customer has one datastore to multiple LUN mapping as belowas they added another LUN to expand the datastore earlier :

Datastore name lun mappedto / lun id / protocol

FTPHdd /vol/Luns/FTPhdd sps1 3 FCP

VMMESX /vol/Luns/VMMESX sps1 8 FCP

/vol/Luns/VMMESX1 sps1 9 FCP

VMHDD /vol/Luns/Vmhdd sps1 1 FCP

VmStore /vol/Luns/Vmstore sps1 2 FCP

Templates /vol/SataVol/Template sps1 7 FCP

VMHDD1 /vol/SataVol/Vmhdd1 sps1 4 FCP

/vol/SataVol/Vmhdd1add sps1 10 FCP

1)When we map the new LUNs on the same ESX host, how do weensure that the datastore to LUN mapping remains as it is in the currentscenario as above.?

2)Do we need to manually add the datastores as per theproecedure http://www.vmware.com/pdf/vsphere4/r40/vsp_40_san_cfg.pdf(page 74)?If yes how do we ensure the mapping of one datastore to 2 LUNs?

Environmentdetails :

VMware ESX,4.0.0,208167

ONTAP 7.3.2 on FAS3140

Protocol : FCP

Anypointers will be much appreciated.

KindRegards,

Sarbjit

Re: question on datastore mapping to multiple LUNs

bondbhola — Wed, 12 Sep 2012 14:46:02 GMT

I am also looking answer of this question..

Re: question on datastore mapping to multiple LUNs

scottgelb — Wed, 12 Sep 2012 15:08:28 GMT

Old question and glad it came back up since most are on 8.0 now and this one wasn't answered... if you are on ONTAP 8.0 or higher, then the "vol move" command can be used (data motion for volumes). Vol Move in 7-mode is only supported for SAN volumes (nothing with an nfs export or cifs share)...but a good use case to move from sata to fc without the hosts knowing. Also, Storage vMotion is another option but would take more time and use the host with some overhead...but maybe a better option for someone on ONTAP 7.3

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question on datastore mapping to multiple LUNs

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