Hello All,

We are considering on setting up 3 node vsan cluster. Each host have 1 TB * 10 Disk= 10 DISK. We are considering to have 2 disk group of 4 capicity disk and 2 disk as cache on each node. We are considering using FTT policy of 1 with RAID 1 setup. My question is regarding the disk usage. As one host is used as witness node, will the diskgroup of the witness node be used to store data other than meta data of RAID 1 setup. Will I be able to use all the diskgroups of all three hosts or only 2 host(RAID 1) and 3rd host for witness. If so then I do not see a point in populating my 3rd host with 10 TB disks to just hold meta data. OR will the data be distributed among the disk groups of all 3 hosts so that all my disk gets utilized and will this increase my usable capacity slightly rather than 2 node usage.

Also, if 1 node fails then will I be able to repopulate a new node in the same cluster and will the RAID start rebuilding.

Sorry if my query has been answered already, I have not been able to find the exact answer to my query. 

Thank You.