I wanted to add a local VMFS datastore on a RAID1 set made by 2 SSD disks in a Dell PowerEdhe R640 server running ESXi 6.5 Update 1d.
The server has SD-cards on whivh ESXi was installed in.
I wanted to use the RAID1 virtual disk for storage of local VMDK’s.
However I got an error:
“Cannot change the host configuration”
Strange as on other servers of the same type I was able to create a datastore without an issue.
Simon Seagrave helped me out with his video here.
What I did was:
- start a SSH session using Putty to the ESXi server
- command: ls -lha /vmfs/devices/disks
- search for the disk size which is the same as the disk you want to create the datastore on. In my case the id was
Make sure to use the correct id! Otherwise you might wipe out the SD-disk on which ESXi was installed
- Then type in this command
partedUtil setptbl /vmfs/devices/disks/<id of the disk> msdos
in my case it was
partedUtil setptbl /vmfs/devices/disks/naa.6d0946604530ba002222fdc313539238 msdos
- Then in the vSphere client I was able to create the datastore