Arno Wagner wrote:

RAID for memory? Are you sure you are not talking about ECC,
which is far better for memory? I do not expect this type of really,
really bad engineering out of IBM, unless the customer demands
it (due to incompetence). Care to list a reference?


YES sure!

Go to www.ibm.com do a search for "memory mirrored" you will among other
things find xSeries models and tech papers on this.

http://researchweb.watson.ibm.com/jo.../tremaine.html
and many many other.

And come to think of it there is still the problem of FRU if doing the
redundancy in the SSD itself. So for real life in a sever, no sir RAID
still has its advances - otherwise 24x7 can't be done.

RAID is fine. But RAID for SSDs is just a sign that the technology
is not being understood. The problem here is that while HDDs
a) typically fail as a unit and b) typically notice when they are
failing, RAID makes a lot of sense with HDDs. SSDs are more likely
to fail in memory locations. A quality SSD can compensate with ECC.
If it cannot, then its controller chip is shot )or something very, very
unlikely happened) and it may give arbitrary wrong data to the
user. RAID does not help at all in this case. Of course this is
simplified.

Arno

Still won't do in real life, SSD simply can't be sold as a "never failing
single device". There is no market in highend IT for such a thing!
A solution with the possibility of handling the SSD as a FRU is what it
takes - without question.

Not that I like refering to specific products, but this company I think is
close me my own thinking and the use of SSD's.
http://www.bitmicro.com/solutions_apps_comp_raidsys.php

Now...
Please take a good cup of coffee, and sit down for a while.

Having great new technology coming to market, is well... great :-)
But if 24x7 handling can't be given, then the new technology will have no
place in high end solutions. Solution keeps running while having failed
part replaced is what defines highend storage today - I think.

SSD will be banned to live its hole life in laptops etc.
And "never failing single device" well not good enough for highend storage
solutions..

So even if you are right SSD "technology is not being understood", you have
to understand the storage market better I think.
So to put it as clear as I can, even if you beeing right today about SSD it
will take years (decades) before you could sell such stuff to highend
without extra security.