[CentOS] RAID MD10

Mon Mar 4 16:35:12 UTC 2013
zGreenfelder <zgreenfelder at gmail.com>

On Mon, Mar 4, 2013 at 11:20 AM, John Plemons <john at mavin.com> wrote:
> Raid 10 is a mirrored stripped set of at least 4 driver. You get the
> best of both worlds, data speed and data back up..
> john

yeah, that's the industry standard.   he's asking you to go find and read
wherein they mention that linux md devices can do what they call a
raid 10 on 2 drives.
and then details some of the reasons you might want to do such a thing.

I can't see any reason to go with the sorta raid 10 on only 2 drives.
 from that article, I'd the only sane choice for raid 10 on 2 drives
is the 'far' config on SSD drives.   but that's just my opinion.   I
don't think I'd ever pick raid10 on 2.

from the entry:
"...copies of a block of data are "near" each other or at the same
address on different devices or predictably offset: Each disk access
is split into full-speed disk accesses to different drives, yielding
read and write performance like RAID 0 but without necessarily
guaranteeing that every stripe is on both drives"

which then some (and by murphy's rule will be the most critcal) will
go from being raid 10 to raid0.  and likely 0 on the drive that fails.

Even the Magic 8 ball has an opinion on email clients: Outlook not so good.