Re: OT about Asus, was Re: What is the point of RAID?
On Sun, Nov 09, 2008 at 10:25:29AM -0600, lee wrote:
> On Sun, 9 Nov 2008 08:50:28 -0500
> "Douglas A. Tutty" <firstname.lastname@example.org> wrote:
> > Parts break,
> > redundancy kicks in, change the dead part, still the same computer.
> > If so, you can do that with three cheap i386 boxes.
> Let's say you have a router/firewall/proxy, a fileserver, a mailserver
> and a webserver. How do you make it so that each of these has a backup
> server that automatically and seamlessly kicks in when needed?
Each "box" is two boxes, running OpenBSD with CARP :)
Of course, they're all the exact same hardware and you have a backup
tape for each type of box. When one box dies, you "restore" it to an
off-the-shelf replacement and get its mate redundant again. Then you
fix the broken box.
That's where I got the "three" from: two hot-redundant (i.e. slowly
wearing out) and one cold-spare (slowly ageing out). In the scenario
with multiple pairs of hot-redundant, I've suggested that they could
share the cold-spare.
At some point of scale, you go with something with LPARs and have fewer
overall boxes and higher reliability. Where that point is, I don't
know. I'll never have the money even for something like the IBM p5-570
(up to 16 processors, up to 64 micro-partitions). The last time I
looked, the shared cost of a micro-partition was about $400 each but
gave you the performance of a $1000 server. With LPARs, you don't have
to dedicate 2 to redundancy, since the hardware/firmware takes care of
that at a lower level.
Of course, their $400 per partition/server likely doesn't cover the
service contract. :)