Nagered hard drive;'(..
in [Computer]
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From: Jon Green on 25 Jun 2010 17:23 On 25/06/2010 22:14, Huge wrote: > On 2010-06-25, Jon Green<jonsg(a)deadspam.com> wrote: >> On 25/06/2010 17:28, Clive George wrote: >>> On 25/06/2010 17:03, Jon Green wrote: >>> >>>> I suspect that Mike meant more than just the drives. If you're dealing >>>> with mission-critical data, it's imperative to keep a hot spare RAID box >>>> too, in secure storage away from the building, so that you can bring up >>>> the data set ASAP after a RAID main board failure. There's absolutely no >>>> guarantee that the drive set will work together in a different model or >>>> make -- in fact, it's pretty-much certain they won't. >>> >>> Once you're doing that you may as well have the second RAID (or rather >>> filer) mirrored from the first, and have a truly hot DR system. >> >> That'll work...so long as the backup RAID isn't totalled by the same >> fire or power surge that nargled the primary! > > Umm, the backup RAID needs to be in your DR site ... Depends what you're trying to achieve. If you want to get the RAID services up and running again ASAP when the main controller cooks off, then having the backup onsite ready to go hot makes sense. Probably, as I'd commented to Clive, for best coverage you have primary, onsite shadow, and offsite shadow, for increasingly severe DR. Jon -- SPAM BLOCK IN USE! To reply in email, replace 'deadspam' with 'green-lines'. Blog: http://bit.ly/45cLHw Pix: http://bit.ly/d8V2NJ Website: http://www.green-lines.com/
From: Jon Green on 25 Jun 2010 17:32 On 25/06/2010 21:40, Roland Perry wrote: > The RAID controller in one of my servers does exactly that, it imports > the drive characteristics (and hence the total storage characteristic) > from whatever is plugged in. But I agree it may have to be the same > make, but as that's Compaq it's not a huge issue. I'd say you need a full hardware dupe in hand -- unless you're prepared to bet your job that some other controller could take in your disk set and use it without error or corruption! -- and you've tested it up, down and sideways first, to be sure! It's the usual conundrum: if you insist on a full dupe setup that may never be used, you'll be called out for being profligate -- but if you didn't, and you're now faced with a mission-critical filestore off-line for hours at least, possibly a day or two, you'll be in deep %^&*, and the bean-counter who talked you out of it will be uncharacteristically silent. Jon -- SPAM BLOCK IN USE! To reply in email, replace 'deadspam' with 'green-lines'. Blog: http://bit.ly/45cLHw Pix: http://bit.ly/d8V2NJ Website: http://www.green-lines.com/
From: Jon Green on 25 Jun 2010 17:43 On 25/06/2010 22:14, Huge wrote: > On 2010-06-25, Jon Green<jonsg(a)deadspam.com> wrote: >> On 25/06/2010 16:04, Huge wrote: >>> Nor indeed, my precious collection of techno-junk. I expect somone, somewhere >>> will want it. As I said, the PDP11 and other assorted computing relics >>> already went to Bletchley Park. >> >> Sadly, my beloved 11/70 > > Ooh, big iron! Mine was just an 11/23+ Four steaming full-height cabs of it! Converted to single-phase, from the original three. If I fired them all up at once, domestic ring main dropped to about 50V (at a guess). Them big disks took a huge instantaneous current to spin up. Didn't take long to work out a staged boot procedure... The annoying thing is that I was getting magtapes of data from NASA at the time. But NASA wrote them at 6250bpi, and my tape cab only grokked 1600, so I had a pal at Glasgow Uni down-rate them for me. When (a) I got a PC, and (b) NASA started producing the data on CD-ROM, things got a _lot_ easier! Jon -- SPAM BLOCK IN USE! To reply in email, replace 'deadspam' with 'green-lines'. Blog: http://bit.ly/45cLHw Pix: http://bit.ly/d8V2NJ Website: http://www.green-lines.com/
From: Jon Green on 25 Jun 2010 17:44 On 25/06/2010 21:11, Roland Perry wrote: > In message <ScSdnZVMDrE_UrnRnZ2dnUVZ8sgAAAAA(a)brightview.co.uk>, at > 16:47:11 on Fri, 25 Jun 2010, Jon Green <jonsg(a)deadspam.com> remarked: >>> If you aren't careful, I'll start talking about delay-line memory ;-) >> >> Mercury, I should hope ... the One True DLM! > > No, the one I have is acoustic. Oh, the springy thingy? Jon -- SPAM BLOCK IN USE! To reply in email, replace 'deadspam' with 'green-lines'. Blog: http://bit.ly/45cLHw Pix: http://bit.ly/d8V2NJ Website: http://www.green-lines.com/
From: Clive George on 25 Jun 2010 17:50
On 25/06/2010 22:23, Jon Green wrote: > On 25/06/2010 22:14, Huge wrote: >> On 2010-06-25, Jon Green<jonsg(a)deadspam.com> wrote: >>> On 25/06/2010 17:28, Clive George wrote: >>>> On 25/06/2010 17:03, Jon Green wrote: >>>> >>>>> I suspect that Mike meant more than just the drives. If you're dealing >>>>> with mission-critical data, it's imperative to keep a hot spare >>>>> RAID box >>>>> too, in secure storage away from the building, so that you can >>>>> bring up >>>>> the data set ASAP after a RAID main board failure. There's >>>>> absolutely no >>>>> guarantee that the drive set will work together in a different >>>>> model or >>>>> make -- in fact, it's pretty-much certain they won't. >>>> >>>> Once you're doing that you may as well have the second RAID (or rather >>>> filer) mirrored from the first, and have a truly hot DR system. >>> >>> That'll work...so long as the backup RAID isn't totalled by the same >>> fire or power surge that nargled the primary! >> >> Umm, the backup RAID needs to be in your DR site ... > > Depends what you're trying to achieve. If you want to get the RAID > services up and running again ASAP when the main controller cooks off, > then having the backup onsite ready to go hot makes sense. > > Probably, as I'd commented to Clive, for best coverage you have primary, > onsite shadow, and offsite shadow, for increasingly severe DR. It's possibly more likely that we'll lose a site than we'll lose a RAID controller/filer - comms (think JCB), air con, power seem flakier than our decent hardware :-) Primary and offsite DR/shadow works well for us. The filers can cope with loss of quite a lot - redundant raid controller/head, obviously RAID 6 + hot spare disks, redundant SAN kit. Also the offsite DR is good enough to be used live. I don't think it's worth spending any more on a full onsite mirror. 'Course we're not really talking about simple file servers here :-) |