Stripe-unit size

With RAID technology, data is striped across an array of physical disks. This data distribution scheme complements the way that the operating system requests data.

The granularity at which data is stored on one disk of the array before subsequent data is stored on the next disk of the array is called the stripe-unit size. The collection of stripe units, from the first disk of the array to the last disk of the array, is called a stripe.

For PCI-X and PCIe controllers, you can set the stripe-unit size of an IBM® SAS Disk Array to 16 KB, 64 KB, 256 KB, or 512 KB. You might be able to maximize the performance of your disk array by setting the stripe-unit size to a value that is slightly larger than the size of the average system I/O request. For large system I/O requests, use a stripe-unit size of 256 KB or 512KB. The recommended stripe size will be identified on the screen when you create the disk array.

For PCIe2 or PCIe3 controllers, you can only set a stripe-unit size of 256 KB. This stripe-unit size has been selected to provide the optimum performance when used with both HDDs and SSDs.