PHOBOS - Re: drbd (was nmbd)

[Ben Lindstrom]

On Tue, 9 Nov 1999, George Bonser wrote:

> > 
> > There is a point of disagreement with Ben though, i.e. the extent to wihch i 
> > can, and are willing to move the stuff/logic into hardware. Hardware has 
> > COSTS... so it's a critical balance (to be figured out by the final HA 
> > implementor/designer/planner), between the software components and the 
> > hardware components he wants to plug-in. So the design of HA needs to be 
> > such that modules/solutions can be plugged in, i.e. if i want i may add 
> > SSLized card, or use it as a software module, if i want link-aggrregation on 
> > card - i go out buy one and use it, else i put in a software based 
> > link-aggregation (ethernet link level load-sharing, balancing, with higher 
> > aggregate bandwidth). Adding a PHOBOS, SSL card, and 4 port FT NIC might 
> > cost quite high, and make the Linux-HA solution "not-so-interesting" a 
> > thing.
> 
> Cost is relative. If my site generates $100K of revenue per day and I have
> the choice of buying a $2K piece of hardware that improves the performance
> more than $50K worth of additional computers and $5K/month of co-lo space
> rent I am a hero. If I install more software that costs nothing but
> requires me to add 10 more systems to take advantage of it, I have not
> gained anything.
> 
> In other words, a piece of hardware that makes an existing system 100
> times more efficient is a better bargain than a piece of software that
> allows me to add 100 systems to get the same throughput.
> 
So you throw in a $2k card that in 2 months goes bad..Your site is down
for 2 days while you get a FedEx package over nighted with the new
hardware and a day to drive out and fix it (as we know.. Just in Time
Inventory..)..  So you loose $200k of revenue and you have a shitload of
angry people.  Instead of having a single box out of 10 go out.. maybe
loose 10k for the two days you're down due to the fact your cluster is
running at 80% load instead of 50% where you rated it out for "normal"
usage. 

=) Good cost savings.