Multi-machine mirroring choices

[Pete French]

> However, I must ask you this: why are you doing things the way you are?
> Why are you using the equivalent of RAID 1 but for entire computers?  Is
> there some reason you aren't using a filer (e.g. NetApp) for your data,
> thus keeping it centralised?

I am not the roiginal poster, but I am doing something very similar and
can answer that question for you. Some people get paranoid about the
whole "single point of failure" thing. I originally suggestted that we buy
a filer and have identical servers so if one breaks we connect the other
to the filer, but the response I got was "what if the filer breaks?". So
in the end I had to show we have duplicate independent machines, with the
data kept symetrical on them at all times.

It does actually work quite nicely actually - I have an "'active" database
machine, and a "passive". The opassive is only used if the active fails,
and the drives are run as a gmirror pair with the remote one being mounted
using ggated. It also means I can flip from active to passive when I want
to do an OS upgrade on the active machine. Switching takes a few seconds,
and this is fine for our setup.

So the answer is that the descisiuon was taken out of my hands - but this
is not uncommon, and as a roll-your-own cluster it works very nicely.

-pete.