On Wed, Aug 05, 2026 at 09:44:42PM -0400, Stefan Monnier wrote:
RAID-5 and RAID-6 rebuild of 8 drive array would take a very long time,
because not only it will have to recover (not just copy) the data from
error correction data spread across all drives
Reading the data from all the drives is a positive rather than a negative:
it means the controller is reading from say, 7 drives to build data on
1. That means a lot more idle cycles on the 7 as opposed to having 1 drive
100% busy (which matters if you're trying to use the array during the
rebuild).
But you need to read all "other blocks" to compute a given missing
block, so it takes 6x more reading to rebuild your array than with
a raid 1/10.
Who cares; if it takes less time to read those blocks, why does it
matter? The limitations on modern hardware aren't the same as they were
30 years ago.
