>[0] I know there are a lot of "configurations" (1 shelf, 2 shelves,
>etc.) but what I mean is if you buy one shelf, most people will, and
>NetApp recommends, keeping 1 disk as a parity drive and 1 as a hot
>spare.  Sure, one could create a RAID group with 7 data drives and no
>parity and hot spare, but I doubt that is "common."

Is it possible with ONTAP to create a volume without a parity disk?  I've got a bunch o' data that would function fine on a RAID-0 type volume... (SAS Tempfiles, holding tank for data transfers, etc...)

I didn't think it was possible... If it is, I've got a use for it.

-john

John Witham
Senior Data Networking Engineer
Takeda Pharmaceuticals North America, Inc.
V://847.383.3304
F://847.383.3205
mailto://jwitham@takedapharm.com

-----Original Message-----
From: Todd C. Merrill [mailto:tmerrill@mathworks.com]
Sent: Wednesday, February 21, 2001 2:44 PM
To: listsarch-toasters@enteract.com
Cc: 'toasters@mathworks.com'
Subject: RE: F85 series

On Tue, 20 Feb 2001, White, Lance wrote:

> performance...so, I ask again (hypothetically, that is), realistically, how
> SHOULD a vendor quote storage capacity?!?

        ...with the most common configuration [0], accepting
the default numbers and vendor's recommended operating configurations.
In NetApp's case, filers with shelves should be quoted retaining a
parity and hot spare drive with the default WAFL overheads and 20%
snapshot reserve.

        Think of it this way:  when a typical customer orders a filer
he opens it up, plugs it in, gives it a name and a few network numbers,
and <poof> how much space does he see?  *That* should be the number in
the quoted literature.

        Specifically, if we were considering the case of the
self-contained F85, this would be (6 drives minus 1 parity minus 1 hot
spare) 4 x 36 GB drives, minus ~10% filesystem minus ~20% snapshot
reserve, for a total usable space of roughly 100 GB.  In this way, there
is no suprise to the customer; management isn't upset that the "216 GB"
file server (36x6) they paid for is only giving them half of that to
use; etc.

        Vendors can say also there is a "maximum usable" configuration
available; "however, some important features may not be available in
this configuration.  Your SE can help you decide what is right for your
installation."  For instance, you could quote a "maximum usable" capacity
of 162 GB, which is 5 drives (sacrificing the hot spare) and no snapshot
reserve (5x36x0.9).

        All IMHO of course.

        I've got a small spreadsheet which takes the disk capacity and
number of drives and calculates this for me, 'cause I know the marketing
capacities are useless.

[0] I know there are a lot of "configurations" (1 shelf, 2 shelves,
etc.) but what I mean is if you buy one shelf, most people will, and
NetApp recommends, keeping 1 disk as a parity drive and 1 as a hot
spare.  Sure, one could create a RAID group with 7 data drives and no
parity and hot spare, but I doubt that is "common."

        Until next time...

The Mathworks, Inc.                             508-647-7000 x7792
3 Apple Hill Drive, Natick, MA 01760-2098       508-647-7001 FAX
tmerrill@mathworks.com                          http://www.mathworks.com
---