vSAN Stripe Width

[seamusobr1]

We have a number of stretched clusters all flash.

Most of out our VMs have a stripe width of 4 which I know is bad but was done before I joined the company

My question is if we reduce the stripe width of 4 to 1 (VMware recommendation) will we see a reduction in read/write IO amplification

Our number one goal is to reduce the load on the back end

Thanks in advance

[T180985]

Obviously you will still have the raid overhead but you might find you will reduce ssd write amplification, its going to be dependent on quite a few factors such as IO size & Block size etc.

Are you seeing performance issues?

[seamusobr1]

thanks for your reply

Yes sort of as we have not isolated vsan traffic and it is sharing it with other traffic types but there is reluctance to use Netioc

When you look at the stats for the nic there are quite a few total receive errors which should indicate we may need to increase the rx buffer size on the nic

The cards are 25GBPs

For some of the VMs we have isolated the copy to the preferred site as the application is clustered and changed the storage policy to mirroring

Just wondering if there is any formula that would show how much reduction in write amplification I would get if I changed the stripe width from 4 to 1