On Wed, Dec 2, 2009 at 9:48 PM, Christopher G. Stach II <cgs at ldsys.net>wrote: > > ----- "Grant McWilliams" <grantmasterflash at gmail.com> wrote: > > > Interesting thoughts on raid5 although I doubt many would agree. > > That's okay. We all have our off days... Here's some quality reading: > > http://blogs.sun.com/bonwick/entry/raid_z > http://www.cyberciti.biz/tips/raid5-vs-raid-10-safety-performance.html > http://www.miracleas.com/BAARF/RAID5_versus_RAID10.txt > http://www.miracleas.com/BAARF/1.Millsap2000.01.03-RAID5.pdf > http://www.codinghorror.com/blog/archives/001233.html > http://web.ivy.net/carton/rant/ml/raid-raid5writehole-0.html > > Maybe you are thinking of RAID 6. > > > I don't see how the drive type has ANYTHING to do with the RAID > > level. > > IOPS, bit error ratio, bus speed, and spindle speed tend to factor in and > are usually governed by the drive type. (The BER is very important for how > often you can expect the data elves come out and chew on your data during > RAID 5 rebuilds.) You will use those numbers to calculate the number of > stripe segments, controllers, and disks. Combine that with the controller's > local bus, number of necessary controllers, host bus, budget, and other > business requirements and you have a RAID type. > > > a RAID 10 (or 0+1) will never reach the write... performance of > > a RAID-5. > > (*cough* If you keep the number of disks constant or the amount of usable > space? "Things working" tends to trump CapEx, despite the associated pain, > so I will go with "amount of usable space.") > > No. > > -- > Christopher G. Stach II > > Nice quality reading. I like theories as much as the next person but I'm wondering if the Toms Hardware guys are on crack or you disapprove of their testing methods. http://www.tomshardware.com/reviews/external-raid-storage,1922-9.html Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos-virt/attachments/20091203/6fd5f65f/attachment-0006.html>