Nagered hard drive;'(..
in [Computer]
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From: Clive George on 25 Jun 2010 12:28 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. > > Yes, I'm assuming that any sensible sysadmin's doing verified regular > backups and off-site storing them, but bringing up a whole new RAID from > scratch, using backups, with a new disk set takes ages. If you can just > pull the drives, jam 'em into the hot spare and be up again in ten > minutes (to include config transfer) instead, you'll be the star of the > show. 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. Obviously there's redundant main boards in the raid setups too :-)
From: Jon Green on 25 Jun 2010 13:22 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! It won't absolve you from having the hot (well, warm, since it's not connected or running) spare and the backups off-site for full disaster recovery. So now you've got three sets of kit! Primary, local mirror, off-site hot spare.) 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 13:29 On 25/06/2010 18:22, Jon Green 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! I did make the assumption that the backup RAID was at a different site :-) > It won't absolve you from having the hot (well, warm, since it's not > connected or running) spare and the backups off-site for full disaster > recovery. > > So now you've got three sets of kit! Primary, local mirror, off-site hot > spare.) Nah, just two - Primary, off-site hot spare/mirror.
From: Bob Eager on 25 Jun 2010 14:43 On Fri, 25 Jun 2010 15:08:47 +0100, Roland Perry wrote: > In message <88jcpkFs8lU7(a)mid.individual.net>, at 09:56:04 on Fri, 25 Jun > 2010, Huge <Huge(a)nowhere.much.invalid> remarked: >>> In mid 70's I worked on ICL drives, including something they called a >>> "drum", which was a single-platter mounted vertically. >> >>You sure it was a "platter"? Only, when I worked for ITT in around >>1975/6 (on what became the Unimat 4080 telephone switch), the message >>switches that we shared our computer room with definitely had drums that >>were drum shaped. > > Absolutely sure. It was in ICL's in-house computer room in Bracknell, > and I was one of those engineers allowed to wander around and look at > anything I wanted to. In the hope that one day, when it broke, I could > try to fix it. I say "day", more like "half an hour". Connected via an SFC - a Sectored File Controller, I believe. I have source code for driving it right here.....! We used it as a 'fast' paging area, but it wasn't that marvellous, so I think we gave up in the end, faster to use the ordinary disk as pages often spilled from it to disk anyway. This was on a homebrew operating system for the 2900. -- Use the BIG mirror service in the UK: http://www.mirrorservice.org *lightning protection* - a w_tom conductor
From: Bob Eager on 25 Jun 2010 14:44
On Fri, 25 Jun 2010 15:04:19 +0100, Roland Perry wrote: > In message <88jcelFs8lU6(a)mid.individual.net>, at 09:50:13 on Fri, 25 Jun > 2010, Huge <Huge(a)nowhere.much.invalid> remarked: > >>(I thought it was an NCR/Elliott 4130? Or were they subsumed into ICL?) > > I started on an ICL 4120 which was an Elliott design, but inside ICL by > late 60's. Yes, that was the detuned 4130. Main differences were a lot of instructions implemented by software extracodes, and no multiprogramming support. -- Use the BIG mirror service in the UK: http://www.mirrorservice.org *lightning protection* - a w_tom conductor |