Re: SAN vs Internal Disks

On Tue, Sep 11, 2007 at 05:09:00PM -0400, Michael Stone wrote:
> On Tue, Sep 11, 2007 at 03:55:51PM -0500, Decibel! wrote:
> >Also, to reply to someone else's email... there is one big reason to use
> >a SAN over direct storage: you can do HA that results in 0 data loss.
> >Good SANs are engineered to be highly redundant, with multiple
> >controllers, PSUs, etc, so that the odds of losing the SAN itself are
> >very, very low. The same isn't true with DAS.
>
> You can get DAS arrays with multiple controllers, PSUs, etc.  DAS !=
> single disk.

It's still in the same chassis, though, which means if you lose memory
or mobo you're still screwed. In a SAN setup for redundancy, there's
very little in the way of a single point of failure; generally only the
backplane, and because there's very little that's on there it's
extremely rare for one to fail.
--
Decibel!, aka Jim Nasby                        decibel@decibel.org
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)