The current version of vSphere, there are two supported VMFS versions for datastore VMFS3 and VMFS5. If you are using any ESXi host prior then 5.0 then you have datastore with VMFS3 file system in your environment. When you are going to upgrade your ESXi into 5.0 or later then you need latest VMFS5 version for datastore in order to use latest VMFS5 features.
Before upgrading keep following things in mind
- In-place upgrade does not provide all the benefits available to a newly created VMFS-5 datastore. These benefits include optimized block size, optimized sub-block allocation, and the use of VAAI (which requires that the VMFS datastores have the same block size).
- It is highly recommended to free the datastore using Storage vMotion and reformat it with VMFS-5.
- The disk type of an upgraded VMFS 3 datastore will remain as MBR until it is grown larger than 2TB. At this point it will be converted to a GPT disk automatically
- Datastore upgrade can be performed even it has VM and they are in running state.
- After you upgrade a datastore, you cannot revert to the previous version
If you see in the Below Screenshot, I have one datastore in my environment. Which has VMFS3 file system and I am going to upgrade it toVMFS5.
Note its “file system” and “block size” as highlighted.
Same can be seen from Webclient as well. There is one thing extra in the webclient view. This is “Maximum file size” of the datastore.
You can reach here from you webclient-> home-> Datastore-> Select your datastore -> Manage -> Settings-> General.
To start upgrade. Click on the “Upgrade to VMFS-5” button.
Select your datastore for upgrdation and make sure you have all hosts which are connected to this datastore have ESXi version 5.0 or above -> Click “OK”
Datastore has been upgraded. You can check his information. It showing now “maximum file size is 64TB” and “VMFS 5.60”, but other interesting thing is upgrade did not change his block size.
Below is the example of a VMFS5 datastore which was formatted with VMFS5 file system and not upgraded into VMFS5. The default block size of newly formatted datastore is “1 MB”. So keep these things in mind.