raid10 physical layout?

raid10 physical layout?

[Matt Garman]

I'm looking into building a six-disk raid10.  The six disks are
comprised of three from one manufacturer, and three from another.

My intuition says that for better statistical reliability, the
redundant data copies ought to fall on disks of different
manufacturers.  I know I could achieve this easily by building a
"classic" RAID1+0 system: three RAID-1 sets built by
manufacturerA+manufacturerB pairs, then striping those mirrored sets
in RAID-0.

But based on what I've been reading, looks like mdadm's more
sophisticated raid10 layout schemes give better performance.  For
example, can I create a raid10,f2 set in such a way as to meet my
"redundant copies on different manufacturer" criteria?

Thanks,
Matt

Re: raid10 physical layout?

[Phil Turmel]

On 05/24/2013 02:49 PM, Matt Garman wrote:
> 
> I'm looking into building a six-disk raid10.  The six disks are
> comprised of three from one manufacturer, and three from another.

> But based on what I've been reading, looks like mdadm's more
> sophisticated raid10 layout schemes give better performance.  For
> example, can I create a raid10,f2 set in such a way as to meet my
> "redundant copies on different manufacturer" criteria?

Just alternate the manufacturers when you list the devices in the
"--create" operation.  MD lays out raid10,f2 redundant data on adjacent
disks.  (Wraps around.)

Phil

Re: raid10 physical layout?

[Roy Sigurd Karlsbakk]

> > I'm looking into building a six-disk raid10. The six disks are
> > comprised of three from one manufacturer, and three from another.
> 
> > But based on what I've been reading, looks like mdadm's more
> > sophisticated raid10 layout schemes give better performance. For
> > example, can I create a raid10,f2 set in such a way as to meet my
> > "redundant copies on different manufacturer" criteria?
> 
> Just alternate the manufacturers when you list the devices in the
> "--create" operation. MD lays out raid10,f2 redundant data on adjacent
> disks. (Wraps around.)

You also may want to consider using LVM instead of md RAID-10, since the latter isn't very flexible - you can't add new drives or otherwise grow raid-10 (atm).

Vennlige hilsener / Best regards

roy
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