Re: [gentoo-user] {OT} Need a new server

[Michael Orlitzky]

On 09/16/2013 02:49 AM, Grant wrote:
>>
>> If it's Type 2, then four drives with a spare is equally tolerant.
>> Slightly better, even, if you take into account the reduced probability
>> of 2/5 of the drives failing compared to 2/6.
>
> Thank you very much for this info.  I had no idea.  Is there another
> label for these RAID types besides "Type 1" and "Type 2"?  I can't
> find reference to those designations via Google.

Nothing standard. RAID 10 pretty intuitively comes from RAID 1+0, which
can be read aloud to figure out what it means: "RAID 1, plus RAID 0,"
i.e. you do RAID 1, then stripe (RAID 0) the result.

The trick is that RAID 1 can refer to either mirroring (2-way) or
multi-mirroring (3-way) [1]. In the end, the designation is the same:
RAID 1. So if you stripe either of them, you wind up with RAID 10. In
other words, "RAID 10" doesn't tell you which one you're going to get.

If I ever find a controller that will do multi-mirroring + RAID 0, I'll
let you know what they call it =)


[1] http://www.snia.org/tech_activities/standards/curr_standards/ddf