Hi. Need some advice please.
I would like to reformat all VMFS3 datastores to VMFS5 without unmapping the LUN on Storage and creating a new LUN.
I know the correct way to remove a datastore from ESXi 5 is to first unmount the datastore and then detaching the device (UUID) from each host. But I would not like todo this, I want to keep all UUIDs the same and not assign new LUNs.
Is there a correct way to-do this, deleting the datastore from a host (which means it’s still mapped, the VMFS is just deleted?) and then adding it again and formatting it with VMFS5, is this the correct way?
Welcome to the Community - This document should help out - http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=200381...
From that article they state the following:
"...Upgraded VMFS-5 partitions will retain the partition characteristics of the original VMFS-3 datastore, including file block-size, sub-block size of 64K, etc. To take full advantage of all the benefits of VMFS-5, migrate the virtual machines to another datastore(s), delete the existing datastore, and re-create it using VMFS-5."
This basically means, go the host configuration, storage, right click datastore form the list and select delete. Then go add storage and add the same LUN back only formatting it with VMFS 5 this time around?
And all this without unmapping and creating a new LUN on the SAN?
Yes, re-creating the datastore is sufficient. No need to unmap it. It's basically like re-formatting an NTFS partition on a Windows host, except ESXi uses it's VMFS file system as the partition type.