----- "Grant McWilliams" <[email protected]> wrote:
> On Wed, Dec 2, 2009 at 9:48 PM, Christopher G. Stach II < > [email protected] > wrote: > > ----- "Grant McWilliams" < [email protected] > wrote: > > > 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 They used a constant number of disks to compare two different hardware implementations, not to compare RAID 5 vs. RAID 10. They got the expected ~50% improvement from the extra stripe segment in RAID 5 with a serial access pattern. Unfortunately, that's neither real world use nor the typical way you would fulfill requirements. If you read ahead to the following pages, you have a nice comparison of random access patterns and RAID 10 coming out ahead (with one less stripe segment and a lot less risk): http://www.tomshardware.com/reviews/external-raid-storage,1922-11.html http://www.tomshardware.com/reviews/external-raid-storage,1922-12.html -- Christopher G. Stach II _______________________________________________ CentOS-virt mailing list [email protected] http://lists.centos.org/mailman/listinfo/centos-virt
