Re: [gentoo-user] dmraid, mdraid, lvm, btrfs, what?

[Mark Knecht <markknecht@gmail.com>]

On Tue, Nov 29, 2011 at 11:02 AM, Jarry <mr.jarry@gmail.com> wrote:
> On 29-Nov-11 17:53, Michael Mol wrote:
>
>>> 1) First lesson - not all hard drives make good RAID hard drives.
>>
>>
>> What makes a good RAID unit, and what makes a terrible RAID unit?
>
>
> Some hard-drives are not suitable for raid at all. There
> are many reasons for that, one example is error-recovery.
> Check wiki for more info:
>
> http://en.wikipedia.org/wiki/Time-Limited_Error_Recovery
>
> In the first place, I would not recommend those "eco" and
> "green" versions for raid at all. They have some saving
> mechanisms which tend to activate at wrong time and cause
> problems for raid-controllers (be it SW or HW). I'd say
> it is worth to pay a few bucks more for enterprise-class
> 24/7 (or special "raid-edition") drives.
>
> Jarry

This is a good representation of what happened on my first pass with
RAID. I bought a bunch of WD 1TB Green drives. They work fine, but
when I put them together in even a RAID1they had very long wait times
in 'top' and the speed was horrible.

That's not to say all Green drives do this because they don't. It's
just hard to say what will work before you buy the drives _unless_ you
buy RAID edition drives.

In Micheal's case he already has his drives so the will either work or
they won't. That's one reason I suggested he put together a couple of
configurations. He's looking at RAID5 & RAID10, which to me makes
sense with 4 drives. We'll just have to wait and see how they work I
think.

- Mark