Upgrading VMFS datastores after migrating to vSphere 6?

By | December 26, 2016

Recently I got the following question from my customer:

Can I mount a datastore formatted under vSphere 6.0 to the vSphere 5.1 or 5.5 host?

I answered: yes, it should work fine because there is the same major version of VMFS but I needed to confirm it, it's me 🙂 I have not able to find any information about it so I decided to check it. vSphere 6.0 introduced VMFS version 5.61  and for a quick reminder we can meet the following VMFS 5 versions:

vSphere 5.5 - 5.60

vSphere 5.1 - 5.58

vSphere 5.0 - 5.54

I could not find any changelog about difference between above versions 🙁

I did a quick test and created a small datastore under vSphere 6.0 and later mounted it to vSphere 5.5 U2. It worked without any problems:Upgrading VMFS datastores after migrating to vSphere 6.0

To check VMFS version from the ESXi CLI, please use vmkfstools --queryfs -h /vmfs/volumes/datastore_name 🙂 Of course, you can also check via GUI (Web Client or vSphere Client), however I prefer CLI 😛

You can not use any tool to upgrade/convert VMFS 5.54-5.60 to 5.61. If you use vmkfstools -T  you will get the following error:

/vmfs/volumes/xxxxxx with version 5 cannot be upgraded.

Error: Operations not supported

Upgrading VMFS datastores after migrating to vSphere 6.0 2

To upgrade VMFS 5.60 to 5.61 you need reformat datastore manually, but for what? 🙂

If you still use VMFS 3, you can use the above command to upgrade the datastore to VMFS 5.

Update 12.2016: vSphere 6.5 introduced a new version of VMFS - 6. If you want to upgrade datastore to VMFS 6, you need to re-format it.

Author: Mariusz

Architect (~ 15 years experience based on passion...) with strong background as a System Administrator and Engineer. Focused on Data Center Solutions: Virtualization/Cloud Computing and Storage/Backup Systems. Currently living in Poland.