[Hidden-tech] Seeking advice on protecting a Linux box from failures

[Michael Leuchtenburg]

On 2011-08-25 14:05, Daniel Belmont wrote:
> I have a special purpose Linux machine that is used to run musical
> instruments and is used frequently in concert settings ... so
> preventing failure is of importance ... I am looking for advice on
> two things :
>
> 1) I need a UPS that produces pure sine waves, has reliable battery
> backup that will instantly kick in during voltage dips, isn't too
> heavy (or wildly expensive), rack mountable would be nice (but I can
> deal with something that is around 25 pounds even if it is not rack
> mountable), and does voltage regulation ... someone suggested that
> there are UPS's that always provide power from the constantly
> recharging battery -- that could be interesting ...

There are two major types of UPSes: line-interactive and online. The 
kind which "kicks in during voltage dips" is line-interactive - it 
doesn't work with things with finicky power supplies. Online UPSes 
always provide power from the batteries, so it's much more reliable. 
There are definitely rack mountable online power supplies though be sure 
to check that it's for the right rack standard. I'm not sure whether 
audio and computer rack standards are compatible.

> 2) what kind of care do I need to provide to the Linux box so that
> it works like a mission critical computer ? the right kind of UPS
> seems important, backing up the hard drive is a given (I am doing
> this now) ... are there other things I need to do to treat this
> computer well ? again, since it is a musical instrument I am very
> desirous of eliminating all of the possible causes of failure (to the
> extent that I can) ...

You could build it with no moving parts. No fans, no spinning drive - 
use SSDs. There are lots of low-power systems out there which don't need 
active cooling. It's worth considering RAID1 for the disks so that if 
one fails during a performance, for whatever reason, it won't be a 
problem, though that could be overkill. SSD failure rates are pretty low.

I'd also use a distribution like Debian stable which doesn't have the 
most cutting edge versions of software, but rather has very well-tested 
software with few bugs that're likely to bite you. It might even be 
worth getting it set up so that it works just right and then taking a 
full image and re-imaging it before each performance - that way it 
doesn't change at all. You can just partition the hard drive and image 
half of it into the other half and boot off USB to copy it over.

Cheers,
Michael