RE: DBSPACES and RAID
Seems like a pretty spectacular failure would be required to get past a RAID 5 implementation with a few hot spares. A failure that spectacular might take out mirrored disks as well. And if this person is going from straight disks, no mirroring, to RAID 5, performance might suffer, but at least there would be a chance of losing a disk and not losing your system. Will >===== Original Message From "Obnoxio The Clown" <obnoxio@hotmail.com> ===== >From: harryjohnson@my-deja.com >> >>In article <aeldhseu.fsf@localhost.localdomain>, >> Thomas Parsli <thomas.parsli@startsiden.no> wrote: >> > "Obnoxio The Clown" <obnoxio@hotmail.com> writes: >> > >> > > From: johnh <john.horton@cognito.co.uk> >> > > >> > > >Has anyone had any experience of setting up DBSPACES on a RAID 5 >>machine >> > > > >> > > >(in particular - running linux) >> > > >I'm trying to make sure that there won't be any problems when I do >>the >> > > >final port off the (un-RAIDed) HP machine to a RAIDed linux box - >>so >> > > >would appreciate any advice in this area >> > > >Thanks very much in advance for helpful hints, advice and horror >>stories >> > > > >> > > >on this issue ! >> > > >> > > I have just this week lost a production RAID-5 box. The demise was >>as >> > > spectacular as it was sudden. In fifteen years, I have never seen a >>box go >> > > like that. I wouldn't touch RAID 5 with someone else's keyboard. >> > > >> > > Don't do it. Really. >> > >> > Tell me more, tell me more! >> > >>I agree. We have found that RAID-5 is 20 to 30 percent (sometimes more) >>slower than using RAID 0+1 when there are a lot of writes. If it is >>just reads, it's ok. > >I don't even care about the performance. If it loses your production >database without any warning, I don't think performance even compares as an >issue. >______________________________________________________ >Get Your Private, Free Email at http://www.hotmail.com ------------------------------------------------------------ This e-mail has been sent to you courtesy of OperaMail, as a free service from Opera Software, makers of the award-winning Web Browser, Opera. Visit us at http://www.opera.com/ or our portal at: http://www.myopera.com/ Your free e-mail account is waiting at: http://www.operamail.com/ ------------------------------------------------------------
Not at all. I could detail a few scenarios where RAID5 will croak. It's architecturally flawed. Check out Art's postings. BTW: we have a disaster recovery customer who disclosed to us that the last 5 times they were required to provide site backups it was down to supposedly safe RAID5 systems just losing their marbles - Oops! I've got no data - as simple as that. No amount of spare disks were any help. However, you are right that RAID5 protection is better than nothing - it *will* catch straight disk failures. Just don't bet your business on it. ---------- In article <87pa71$ge3$1@news.xmission.com>, William Rice <ricew@operamail.com> wrote: Seems like a pretty spectacular failure would be required to get past a RAID 5 implementation with a few hot spares. A failure that spectacular might take out mirrored disks as well. And if this person is going from straight disks, no mirroring, to RAID 5, performance might suffer, but at least there would be a chance of losing a disk and not losing your system. Will