i have 3 nodes with 1 SSD and 3 HDD each. in one of the servers the SSD is broken (after just 2 months of intense stress testing and it's an enterprise SLC).
with the SSD broken, the whole diskgroup is degraded and all VMs should be moved away from them.
so how do i replace the SSD in the group. i can't add a new one to it because a group can only have 1 SSD. i can't remove the old one because the group needs a SSD. when i try to remove the whole group, vcenter warns me i will loose VM's currently put on the disks. i do have VM's that use a policy of failures to tolerate=0.
You have to put the host into maintenance mode with Option "Ensure Accessability" or "Full data migration".
Then you can delete the disk group and create a new one.