Re: 2-disk layout

Posted in 2000

wyn441 — Fri, 11 Aug 2000 16:02:56 -0700 — source: Informix-list mailing list archive (1991-1998)

"Art S. Kagel" <kagel@bloomberg.net> wrote: > NO RAID5 NO RAID5 NO RAID5 NO RAID5 NO RAID5 NO RAID5 NO RAID5 > >wyn441 wrote: >> >> RAID5 - Independent Data disks with distributed parity blocks - >> minimum 3 disks. Highest Read speed, medium write speed. >> Recommened for: >> File and Application servers >> Database servers > >AAAAAAAAAAAAAAAAAAAAAAAAAA! > >NEVER NEVER NEVER use RAID5 for databases. SSSSLLLOOOWWW writes, 50% >of RAID0 write speed. Prone to catastrophic data loss due to partial >media failure because parity is NEVER checked on read! Thanks for your input, Art. I have only had experience with RAID1, 3, and 5 (and very little with Informix). As it happens our Informix db is on RAID5 (hmmm, maybe that's why it's so slow...) Anyhow, the recommendation came from a hardware manual I have (Yes, I RTFM!) Too bad TFM isn't always right. <drips irony here> >RAID10, stripped sets (RAID0) made of mirrored pairs (RAID1), provides >the besta combination of protection, as good as RAID1, and performance, >as good or slightly better than RAID0, for both reads and writes. >Art S. Kagel I'm very intrigued by this solution. Do you know where I can get more in depth info on it (without buying another FM? I'm running out of dough training myself). Does this RAID solution work well with NT using the ICP Vortex solution you mentioned? Wynne ----------------------------------------------------------- Got questions? Get answers over the phone at Keen.com. Up to 100 minutes free! http://www.keen.com

↪ replying to wyn441

Art S. Kagel — Mon, 14 Aug 2000 14:21:21 -0400 — source: Informix-list mailing list archive (1991-1998)

wyn441 wrote: > > "Art S. Kagel" <kagel@bloomberg.net> wrote: > > NO RAID5 NO RAID5 NO RAID5 NO RAID5 NO RAID5 NO RAID5 > NO RAID5 > > > >wyn441 wrote: > >> > >> RAID5 - Independent Data disks with distributed parity > blocks - > >> minimum 3 disks. Highest Read speed, medium write speed. > >> Recommened for: > >> File and Application servers > >> Database servers > > > >AAAAAAAAAAAAAAAAAAAAAAAAAA! > > > >NEVER NEVER NEVER use RAID5 for databases. SSSSLLLOOOWWW > writes, 50% > >of RAID0 write speed. Prone to catastrophic data loss due to > partial > >media failure because parity is NEVER checked on read! > > Thanks for your input, Art. I have only had experience with > RAID1, 3, and 5 (and very little with Informix). As it happens > our Informix db is on RAID5 (hmmm, maybe that's why it's so > slow...) Anyhow, the recommendation came from a hardware manual > I have (Yes, I RTFM!) Too bad TFM isn't always right. <drips > irony here> > > >RAID10, stripped sets (RAID0) made of mirrored pairs (RAID1), > provides > >the besta combination of protection, as good as RAID1, and > performance, > >as good or slightly better than RAID0, for both reads and > writes. > >Art S. Kagel > > I'm very intrigued by this solution. Do you know where I can get > more in depth info on it (without buying another FM? I'm running FM? Ahh, got it. There is a description of the several of the RAID0, RAID1, RAID4, RAID5, and RAID10 at the Vortex site. See: www.icp-vortex.com/supp/info/levels_e.html > out of dough training myself). Does this RAID solution work well > with NT using the ICP Vortex solution you mentioned? Check out the benchmarks quoted on the ICP-Vortex site under <Performance>. I have not tried them myself but these controllers get GREAT reviews in the press both MS WinDoze and Linux. Art S. Kagel

↪ replying to Art S. Kagel

Thanh — Mon, 14 Aug 2000 19:56:17 GMT — source: Informix-list mailing list archive (1991-1998)

In article <399838A1.47D4FA3B@bloomberg.net>, kagel@bloomberg.net wrote: > wyn441 wrote: > > > > "Art S. Kagel" <kagel@bloomberg.net> wrote: > > > NO RAID5 NO RAID5 NO RAID5 NO RAID5 NO RAID5 NO RAID5 > > NO RAID5 > > > > > >wyn441 wrote: > > >> > > >> RAID5 - Independent Data disks with distributed parity > > blocks - > > >> minimum 3 disks. Highest Read speed, medium write speed. > > >> Recommened for: > > >> File and Application servers > > >> Database servers > > > > > >AAAAAAAAAAAAAAAAAAAAAAAAAA! > > > > > >NEVER NEVER NEVER use RAID5 for databases. SSSSLLLOOOWWW > > writes, 50% > > >of RAID0 write speed. Prone to catastrophic data loss due to > > partial > > >media failure because parity is NEVER checked on read! > > > > Thanks for your input, Art. I have only had experience with > > RAID1, 3, and 5 (and very little with Informix). As it happens > > our Informix db is on RAID5 (hmmm, maybe that's why it's so > > slow...) Anyhow, the recommendation came from a hardware manual > > I have (Yes, I RTFM!) Too bad TFM isn't always right. <drips > > irony here> > > > > >RAID10, stripped sets (RAID0) made of mirrored pairs (RAID1), > > provides > > >the besta combination of protection, as good as RAID1, and > > performance, > > >as good or slightly better than RAID0, for both reads and > > writes. > > >Art S. Kagel > > > > I'm very intrigued by this solution. Do you know where I can get > > more in depth info on it (without buying another FM? I'm running > > FM? Ahh, got it. There is a description of the several of the RAID0, > RAID1, RAID4, RAID5, and RAID10 at the Vortex site. See: > www.icp-vortex.com/supp/info/levels_e.html > > > out of dough training myself). Does this RAID solution work well > > with NT using the ICP Vortex solution you mentioned? > > Check out the benchmarks quoted on the ICP-Vortex site under > <Performance>. I have not tried them myself but these controllers > get GREAT reviews in the press both MS WinDoze and Linux. We are also using RAID 5. Me too, would like to see a convincing technical article why we should be using RAID 10 instead. What I would say to my management is: "Boss, I think we should be using RAID 10 instead of RAID 5. Here is what was written by Art, an expert in Informix and is a co-author of 'The Informix Handbook'". I am new to this company you know and I would like to be backed up by an expert :-) Thanh PS. Could you also comment whether the 2-disk layout is Bad, OK, Good, Great, A-F. Sent via Deja.com http://www.deja.com/ Before you buy.

↪ replying to Thanh

Art S. Kagel — Tue, 15 Aug 2000 14:11:19 -0400 — source: Informix-list mailing list archive (1991-1998)

See my reply to a posting on Dec. 1, 1999 subject: Re: Informix IDS and RAID 5 You can search for it on the IIUG Web Site (I think it shows up there as posted Dec. 2, 1999. Art S. Kagel Thanh wrote: > > In article <399838A1.47D4FA3B@bloomberg.net>, > kagel@bloomberg.net wrote: > > wyn441 wrote: > > > > > > "Art S. Kagel" <kagel@bloomberg.net> wrote: > > > > NO RAID5 NO RAID5 NO RAID5 NO RAID5 NO RAID5 NO RAID5 > > > NO RAID5 > > > > > > > >wyn441 wrote: > > > >> > > > >> RAID5 - Independent Data disks with distributed parity > > > blocks - > > > >> minimum 3 disks. Highest Read speed, medium write speed. > > > >> Recommened for: > > > >> File and Application servers > > > >> Database servers > > > > > > > >AAAAAAAAAAAAAAAAAAAAAAAAAA! > > > > > > > >NEVER NEVER NEVER use RAID5 for databases. SSSSLLLOOOWWW > > > writes, 50% > > > >of RAID0 write speed. Prone to catastrophic data loss due to > > > partial > > > >media failure because parity is NEVER checked on read! > > > > > > Thanks for your input, Art. I have only had experience with > > > RAID1, 3, and 5 (and very little with Informix). As it happens > > > our Informix db is on RAID5 (hmmm, maybe that's why it's so > > > slow...) Anyhow, the recommendation came from a hardware manual > > > I have (Yes, I RTFM!) Too bad TFM isn't always right. <drips > > > irony here> > > > > > > >RAID10, stripped sets (RAID0) made of mirrored pairs (RAID1), > > > provides > > > >the besta combination of protection, as good as RAID1, and > > > performance, > > > >as good or slightly better than RAID0, for both reads and > > > writes. > > > >Art S. Kagel > > > > > > I'm very intrigued by this solution. Do you know where I can get > > > more in depth info on it (without buying another FM? I'm running > > > > FM? Ahh, got it. There is a description of the several of the > RAID0, > > RAID1, RAID4, RAID5, and RAID10 at the Vortex site. See: > > www.icp-vortex.com/supp/info/levels_e.html > > > > > out of dough training myself). Does this RAID solution work well > > > with NT using the ICP Vortex solution you mentioned? > > > > Check out the benchmarks quoted on the ICP-Vortex site under > > <Performance>. I have not tried them myself but these controllers > > get GREAT reviews in the press both MS WinDoze and Linux. > > We are also using RAID 5. Me too, would like to see a convincing > technical article why we should be using RAID 10 instead. What I would > say to my management is: "Boss, I think we should be using RAID 10 > instead of RAID 5. Here is what was written by Art, an expert in > Informix and is a co-author of 'The Informix Handbook'". I am new > to this company you know and I would like to be backed > up by an expert :-) > > Thanh > > PS. Could you also comment whether the 2-disk layout is Bad, OK, > Good, Great, A-F. > > Sent via Deja.com http://www.deja.com/ > Before you buy.