Is it recommended to place host swap files on VMFS datastore cluster? will the SDRS in the swap datastore would help me in terms of performence?
The datastores are VMFS datastores reside on NetApp storage array LUNs exposed over the SAN network (fc protocol). These luns reside on as same physical disks as the data disks on the storage array
For HOST swap it will choose the best location auto. If you have SSD that will be always the best approach instead of an outside storage
For VM swap and so on (aslo host) check this link with best practices and everything will be always based on your current setup and limitations.