on 5-22-2008 9:12 AM Rudi Ahlers spake the following: > Warren Young wrote: >> John R Pierce wrote: >>> raid50 requires 2 or more raid 5 volumes. >>> >>> with 4 disks, thats just not an option. >>> >>> for file storage (including backup files from a database), raid5 is >>> probably fine... for primary database tablespace storage, I'd only use >>> raid1 or raid10. >> >> RAID-10 has only one perfect application, and that's with exactly four >> disks. It can't use fewer, and the next larger step is 8, where other >> flavors of RAID usually make more sense. But, for the 4-disk >> configuration, it's unbeatable unless you need capacity more than >> speed and redundancy. (In that case, you go with RAID-5.) >> >> RAID-10 gives the same redundancy as RAID-50: guaranteed tolerance of >> a single disk lost, and will tolerate a second disk lost at the same >> time if it's in the other half of the RAID. RAID-10 may also give >> better performance than RAID-50. I'm not sure because you're trading >> off more spindles against more parity calculation with the RAID-50. >> At any rate, RAID-10 shouldn't be *slower*. >> _______________________________________________ >> CentOS mailing list >> CentOS at centos.org >> http://lists.centos.org/mailman/listinfo/centos >> > It seems like you know / like RAID-10 a lot :) > > So, how does it perform with 6 discs for example? Say I have 3 HDD's in > RAID-0, and another 3 in RAID-0, then RAID-1 the 2 RAID-0 stripes. How > well would that work? > And what would you recommend on 8 / 10 HDD's? > What you are describing would be raid 0+1 not raid 10. Most docs I have read state that raid 10 is more fault tolerant. Here is one that explains it better; http://www.pcguide.com/ref/hdd/perf/raid/levels/multXY-c.html -- MailScanner is like deodorant... You hope everybody uses it, and you notice quickly if they don't!!!! -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 258 bytes Desc: OpenPGP digital signature URL: <http://lists.centos.org/pipermail/centos/attachments/20080522/fed2e2f4/attachment-0005.sig>