Re: Disk I/O slowness

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.