Linux wrote: > On Fri, May 23, 2008 at 8:28 AM, Guy Boisvert <boisvert.guy at videotron.ca> wrote: >> "More intelligently designed" -> Could you please tell us more on this one? > > Simple answer: Open Source (and for a long time) I guess you know what > it means. But I wander if source of Adaptec raid controller's firmware > is opened in recent years. Well, i respect Open Source (and your opinion) very much but your comparison imply that you had access to Adaptec's code! Maybe you really had access, i don't know. If it's the case, then thanks you for having shared this knowledge. >> >> Not easily recoverable? I did recovery many time without a hitch (Adaptec, >> 3Ware, LSI, PERC)! > > Try recovering 3Ware failed disks with Adaptec then. Nearly every > vendor has his own way in details. Yes, mostly documented but not > interchangable. And I do not mean only RAID-1. You're talking about failed disks or controller? With controller, easy with my backups (or backup card). People with no tolerance to failing controller arrange things accordingly like i do. With disks, irrelevant. > >> As for RAID 10 with 3 disks, mmm... go see: >> >> http://en.wikipedia.org/wiki/Redundant_array_of_independent_disks > > mdadm Raid-10 is neither 1+0 nor 0+1. So 3 disks is enough to supply a > minimum level of redundancy. You should have 2 copies of each stripes > on either 2 of 3 disks. But in 3 disk configuration loss of 2 disk > means total loss. Go check with man mdadm. > Well, educate me (and maybe others) M8. I learn things everyday and i like it. How would you do RAID10 with 3 disks? I know how to do it with at least 4, then 6 and so on. As for RAID-10, more below. > > Well, my parents taught me understanding what I read better than you > (although I'm not a native English speaker) Well, english is neither my native language! As for reading, i'm not that bad but i may have misunderstood what you really meant. In that case, please forgive me! I didn't meant to be rude or anything. > >> Hey, have a nice day "Linuxito" ! > > Thanks buddy. > > And for referance, try reading this  > > I do not want to start a flame, just sharing my experience with > different hardwares. This comparison about software-hardware raid > excludes SAN and other external RAID solutions. Externally attached > storage is outside the scope of this discussion. Externally connected > solutions can obviously be SAN, software RAID, hardware RAID, or a > combination thereof.  > >  http://linux.yyz.us/why-software-raid.html I agree that the compatibility is great with software RAID. However, there are some limitations at least in performance (Bus saturation, etc). I "tried to read" your reference (the URL you kindly provided me, thanks) and, quote: "When the top array is a RAID 0 (such as in RAID 10 and RAID 50) most vendors omit the "+", though RAID 5+0 is clearer." "RAID 1+0: mirrored sets in a striped set (minimum four disks; even number of disks) provides fault tolerance and improved performance but increases complexity. The key difference from RAID 0+1 is that RAID 1+0 creates a striped set from a series of mirrored drives. In a failed disk situation RAID 1+0 performs better because all the remaining disks continue to be used. The array can sustain multiple drive losses so long as no mirror loses both its drives." So they say, and correct me if i'm wrong, that RAID10 is a RAID 1 of RAID 0. A mirror of stripe sets. You said it's not that, i lost you on this one. |-- Mirror ----| | | -- D1a -- D1b | | | Striped | Striped | | -- D2a -- D2b | | ... ... | | -- Dna -- Dnb So that's why i don't get what you mean by RAID10 with 3 disks. Please explain. Guy Boisvert, ing. IngTegration inc.