Before you go too far, check that UPS for power supply noise as it is used both in it's normal environment and with the 117 V power disconnected. Over the past several years I have read in compliance mags that even some FCC approved power supplies are coming from China without the noise suppression filters installed. And there are others that have never been approved. Yes, US Customs is supposed to stop entry of such stuff at the border. One article reported that all two trained agents who service the East & Gulf Coasts were a bit overwhelmed. Jim Ussailis jim at nationalwireless.com Original Message: ----------------- From: Michael Leuchtenburg michael at slashhome.org Date: Thu, 25 Aug 2011 14:40:47 -0400 To: Hidden-discuss at lists.hidden-tech.net Subject: Re: [Hidden-tech] Seeking advice on protecting a Linux box fromfailures ** Be sure to fill out the survey/skills inventory in the member's area. ** If you did, we all thank you. 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 _______________________________________________ Hidden-discuss mailing list - home page: http://www.hidden-tech.net Hidden-discuss at lists.hidden-tech.net You are receiving this because you are on the Hidden-Tech Discussion list. If you would like to change your list preferences, Go to the Members page on the Hidden Tech Web site. http://www.hidden-tech.net/members -------------------------------------------------------------------- myhosting.com - Premium Microsoft® Windows® and Linux web and application hosting - http://link.myhosting.com/myhosting