sony-vaio-z-series team mailing list archive

[Peter Fern <sonylinux@xxxxxxxxxxx>]

On 30/03/10 19:32, Xavier Hallade wrote:
> What I was trying to say was that the raid0 used in the new vaio z is
> not between physical separated drives but between drives that are in
> the same physical package.
> http://forum.notebookreview.com/showthread.php?t=471811
> It's why I think the typical argumentation against raid0 isn't valid ;)

I see - that's interesting, but I think I must still disagree.  Because
they share the same package, you are correct in asserting that there is
a greater risk of two devices failing at once, but only if there is a
failure in the shared components, and since they present to the system
as individual physical devices, I assume this is something like an
embedded port multiplier (would have to get my hands on the hardware to
be sure).  That still leaves the individual drive controllers and flash
on each drive susceptible to independent failure.  So, just because
there's some risk of losing both drives in one package if the shared
component fails, doesn't mean (IMHO) that you should compound the risk
by making your data integrity dependent on all the other components
remaining operation.  I certainly can't see any argument for striping
across all devices in both packages (all four 'drives'), even with the
higher MTBF of SSDs.  And you'll hit the network bottleneck long before
peak load for any I/O that's not locally generated.

I kinda have to wonder though why they didn't just build larger, regular
SSDs rather than adding all this extra complexity into the mix - was it
just so that they could say, "It has FOUR SSDs!!" maybe?  It does smell
a little of marketing gimmick, and looking at some early photos[1], it
means you cannot ever replace the drives with after-market parts, since
they use proprietary connectors.  Just what we need - more proprietary
hardware from Sony making our lives difficult.

Pete.

[1]
http://translate.google.com/translate?js=y&prev=_t&hl=en&ie=UTF-8&layout=1&eotf=1&u=http%3A%2F%2Fchinese.engadget.com%2F2010%2F03%2F04%2Fvaio-z-explained-by-project-leader%2F&sl=zh-CN&tl=en&swap=1