[dm-devel] Barriers still not passing on simple dm devices...

[Mikulas Patocka]

On Sun, 5 Apr 2009, Lee Revell wrote:

> On Sun, Apr 5, 2009 at 7:54 AM, Ric Wheeler <ricwheeler at gmail.com> wrote:
> > One thing to point out here is that there are a lot of "servers" in high end
> > data centers that do not have UPS backup. Those racks full of 1U and 2U
> > boxes that are used to make "grids", "clouds" and so on often are built with
> > as much gear as you can stuff in a rack - no batteries or UPS to be seen, so
> > they are really quite similar to the normal desktop or home systems that we
> > normally run at home :-)
> 
> These days even bargain basement data centers provide UPS functionality for
> you, via generator backup and A/B power.

I have seen an installation having generator backup, but with another 
serious flaw --- if someone plugged a computer causing short-circuit, it 
turned off the circuit breaker for the whole rack :)

Mikulas

> Lee