ECC support

[Igor Mozolevsky]

On 15 September 2015 at 23:34, Jim Thompson <jim at netgate.com> wrote:

<snip>


> I think you’ll find that the default for ‘scrub’ is off on most (perhaps
> all) boards.  There are reasons, and these relate directly to
> “significantly diminish system performance”, (above), as well as the
> greatly increased RAM sizes in use today.
>

Perhaps I missed something- what point is it that you're trying to make? I
was saying that scrubbing aims to remove errors at the source (cf. "on
demand") and prevent multi-bit errors that become detectable but
irrecoverable, or worse, undetectable. Get hit by a few of the latter two
at "interesting" points and you'd wish that scrubbing were on!

And seriously, ECC scrubbing is slow but ZFS (or even hardware RAID)
scrubbing is lightning fast??! C'mon are we going for data integrity or
speed here?!

’Scrub' was popular about a decade ago, when DDR2 RAM was around $100/GB.
> DDR3-1600 is about $6/GB today.
>

Yup- with a much higher density of smaller memory bits! ;-)

-- 
Igor M.