On 7/31/26 01:09, Andy Smith wrote:
Hi,
On Fri, Jul 31, 2026 at 12:04:30AM +0500, Alexander V. Makartsev wrote:
I might add insult to the injury, but are you sure you need RAID-5 if it
consists of just 3 drives?
Usually around 30% per drive's capacity will be sacrificed to hold error
correction data for the array,
so maybe it will be much better to use 2 drives in RAID-1 (Mirror)
configuration, if you need decent write performance.
Third drive could be used as spare device for the array, or a separate
storage without redundancy.
On Linux mdadm you can also do a RAID-10 across three drives which still
allows for the loss of any single drive and provides both better read
and write performance compared to RAID-5 of the same devices. The
capacity would be 1.5 drives as opposed to 2.
That is an interesting idea.
The RAID-10 configuration you proposing should then consist of 3 RAID-1
(mirror) groups, so 3 drives must be partitioned in halves and to finish
RAID-10 array, there should be a RAID-0 (stripe) array created across
all 3 groups.
Will the RAID-0 (stripping) layer of RAID-10 configuration significantly
improve the write performance of the array in comparison to a basic
RAID-1 array?
With the today's abysmal prices of storage devices of any kind, I don't
think I will be able to test this any time soon...
--
With kindest regards, Alexander.
Debian - The universal operating system
https://www.debian.org
