Hey people I've got a question about vSAN Storage Policies, specifically about stripe width. To give some context, we have a 6 node all-flash (NVMe) vSAN cluster. This is a brand new cluster running on Dell R740xd nodes with 3 disk groups per hosts. We also have Deduplication and Compression turned on in the cluster.
I'm going to dumb this down a little bit but from what I understand, setting the stripe width on the vSAN Storage Policy will increase the amount of disks that data is striped across. Theoretically this means that more disks are engaged which should increase performance.
Now all that to get to my questions. Why would you not increase the stripe width and at what point do you see negative returns from changing this setting? A colleague of mine has set all our policies to use a stripe width of 7. We have different policies for Raid-1, Raid-5, and Raid-6, all with 7 stripes. This seems bad to me but I can't articulate why. Does someone have test results that show how different stripe widths affect application performance?