Esxi 6.5 incredibly high io latency scsi poweredge r710

My entire host machine is effected by one guest. Not sure if i have a bad hard drive or what, but when this machine is on, the latency of the entire host esxi gets to where no other vms can run on the data store. Only using 4 cores, and 30gb ram and powered down all other machines running. Need someone to log on diagnose and fix (or if its a bad hard drive, tell me which one is causing it).