ONTAP Discussions

How to snap/clone VMDK using CLI


We have a FAS8200 running Ontap 9.8 with several FC LUNs zoned to an ESX cluster.  One of the VM's has multiple 5TB LUNs/VMDK/datastores containing millions of images mounted to a Windows guest as individual disks.  They are not RDM.  The application is being upgraded with new VM's and they want a full blown copy of all these datastores presented to the new VM's at production cutover time.  They are considering robocopy, emcopy and other host based utils but I am pretty sure we can do this way faster with a snap/clone ... but we've never had need to do this and have no experience.  The process seems logical, snap, create flex clone, map new LUNs to the ESX host(s) but what concerns me is that the source and target VMs are on the same ESX host and the clone target (LUN) disk signature would (?) be identical to the source.  I *think* we should move all of these 5TB LUNs into the same volume for this process.  That suggests that they all need to be on the same aggregate, too (right?) ... and that the aggregate needs to be able to handle "double" the size when we split the clones.  Am I missing anything else?


Can anyone point me to any docs that address how to do this?  Thanks!





Also, during the process of bringing the cloned LUN online, can I map it to the same ESX host(s) as the source LUN (which is still online) and import/mount it and resignature it as it comes online without clobbering the original LUN?  Or does the VMware disk re-scan see it as a duplicate (before the mount) and cause issues at that time?