Filer volumes must have at least one data and one parity drive.
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com]On Behalf Of john@takedapharm.com Sent: Saturday, October 13, 2001 10:32 PM To: tmerrill@mathworks.com; listsarch-toasters@enteract.com Cc: toasters@mathworks.com Subject: RE: F85 series
[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 ---