Re: [SAGE] NetApp--spindles vs. performance

[Doug Hughes <doug@eng.auburn.edu>]

On Mon, 20 Jan 2003, Philip Brown wrote:

> On Thu, Jan 16, 2003 at 02:26:04PM -0600, Doug Hughes wrote:
> >
> > Wide thin striping is another good use of technology to take maximum
> > advantage of performance while minimizing administrative overhead.
> > (http://www.sun.com/solutions/blueprints/1000/layout.pdf)
>
> I wish someone had never come up with that idiotic phrase.
>
> Reminds me of that alchohol commercial (which I just saw today, funnily
> enough)...
> " Did you saySergio, in Rio?  dark, fairhaired, heavy-set thin guy?"
>
> How about using a longer set of words that convey the meaning precicely,
> instead of using only two words, that then require people go download
> the pdf ?
>
> I dont remember if it was advocating wide columns, with few disks, or
> many disks, with narrow columns.  (or some other layout, even)
> "wide thin striping" does not help jog my memory as to the specifics.
>
for those that have not glanced at the pdf (which is a good read)

Abstract:

The technique of using stripes to spread data and indexes over many disks
is described. This disk layout strategy simplifies performance
considerations while achieving reliable and manageable disk farms on large
systems. The technique is compared to a carefully hand-balanced layout for
disk contention and scalability. Hardware mirrroring in conjunction with
host level mirroring or a volume manager capable of creating striped
mirrors is a key enabler. Detailed considerations that database
specialists need to make in order to justify this layout technique are
presented. The recommmendation to use wide-thin stripes to maximize
operational flexibility while minimizing complexity is justified.

---
- take a large number of disks, break them up into a large number of
equally sized regions (subdisks, etc), use a large interlace value,
and make stripes covering a fairly large number of disks. It balances
I/O and maximizes disk and channel/controller usage while minimizing
hotspots.