Linux wrote:
On Fri, May 23, 2008 at 8:28 AM, Guy Boisvert <boisvert.guy@xxxxxxxxxxxx> 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 [1]
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. [1]
[1] 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.
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