From: Walden H. Leverich
All servers WILL GO DOWN. Period. They'll both go down for unexpected
reasons (software/hardware/environment) and for planned reasons
(software/hardware/environment upgrades). What I'm describing is a way
to provide application availability on a 24x7x365 manner at a fraction
of the cost of a single System i, let alone the minimum of two you'd
need to support 24x7x365.
I'm going to avoid most of the debate here, but I am going to make a couple
of points. Take 'em or leave 'em.
First, I question the phrase "fraction of the cost". Please make sure when
you price your Windows solution, you price in tape backup and solid backup
software, neither of which comes with a standard Windows server
configuration (at least that I've seen). The "fraction" becomes a much
higher fraction, and that's when comparing one machine to another.
I'm also going to make sure you're VERY specific about high availability.
In my experience, very few sites need 24x7x365. Nearly every production
system, from banks to storefronts, have periods of scheduled downtime where
all they need is a web page that says "will be back shortly".
With proper journaling and save-while-active, an i5 need only be unavailable
for short, scheduled downtimes. Something like an hour somewhere between
once a month and once a quarter, depending on the workload, primarily to
apply PTFs.
That's something like 99.95% uptime; please identify the situations where
you need more than that. Correct me if I'm wrong, but that level of uptime
for a Windows server typically requires multiple reboots because you have to
apply patches regularly. So unless I'm mistaken (and you'll correct me,
Walden, I'm sure <smile>), it really requires two Windows servers to match
the availability of a single System i for all but the most rigorous
requirements. Add THAT to your "fraction" and I think you might be
surprised which is cheaper.
I'm not arguing that Windows server is much more stable than it used to be.
But I still have a problem saying it's equivalent to the stability of i5/OS,
and the ease of administration of the operating system.
I just want to make sure we're talking about real business needs, not
marketing hype. Personally, I think the phrase "24x7x365" is something of a
marketing hypebole. (Heck, it really should just be "24x365", but I
digress. <grin>)
Joe
midrange.com
