[Discuss] SSD drives vs. Mechanical drives

[bogstad at pobox.com (Bill Bogstad)]

On Mon, May 5, 2014 at 3:50 PM, Richard Pieri <richard.pieri at gmail.com> wrote:
>...
> Repeat after me: redundant disks do not provide data integrity.
>
> Redundant disks -- be they rotating platters or flash chips -- will keep
> the system running if one fails but they won't protect your data from
> corruption or loss.

The way I think of loss; hardware redundancy can protect you
against data loss due to failures which occur in the redundant hardware.
What it can't do is protect you against is loss due to software or
operational errors.
Any hardware that isn't redundant can cause corruption, but proper use
of redundant
hardware (appropriate RAID levels) can protect against corruption caused by
those devices.   I believe that some specialized hardware allow a checksum to
be generated in the system and checked/stored on the storage device in
such a way as
to protect against data path errors.   (A bit like ZFS can do, but
with hardware assistance.)

Bill Bogstad