Hi all, I wanted to ask the collective wisdom out there about how many disks to put in an aggregate.
I have an F825 with 2 DS14 shelves, currently set up as 1 aggregate (so 28 disks in the aggregate), double parity, and 2 spares.
I will be adding another DS14 shelf, identical disks as the other 2 shelves. My preference is to just extend the existing aggregate to 42 disks, and set up another volume for the new data that will be going on there - but I believe NetApp says that 28 disks is the max for an aggregate.
So, question is - anyone out there using more than 28 (like 42 !) disks in an aggregate ? Is it possible ? recommended ? I thought that the more disks the better in an aggregate for performance reasons, but I thought I'd see what you all say !
Thanks,
John
I think the only limitation on an aggregate is the size of the aggregate. The raw max of an aggr is 17TB. So with 500 GIG drives after spares, etc you use 34 Disks. So 500 GIG ata the max aggr is 34 Disks.
With say 144GIG drives you could get 118 Disks in an aggregate.
Hope that helps
(this is on data on tap 7.2)
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of John Foley Sent: Thursday, April 05, 2007 11:30 AM To: toasters@mathworks.com Subject: number of disks in an aggregate ?
Hi all, I wanted to ask the collective wisdom out there about how many disks to put in an aggregate.
I have an F825 with 2 DS14 shelves, currently set up as 1 aggregate (so 28 disks in the aggregate), double parity, and 2 spares.
I will be adding another DS14 shelf, identical disks as the other 2 shelves. My preference is to just extend the existing aggregate to 42 disks, and set up another volume for the new data that will be going on there - but I believe NetApp says that 28 disks is the max for an aggregate.
So, question is - anyone out there using more than 28 (like 42 !) disks in an aggregate ? Is it possible ? recommended ? I thought that the more disks the better in an aggregate for performance reasons, but I thought I'd see what you all say !
Thanks,
John
On Apr 5, 2007, at 11:29 AM, John Foley wrote:
new data that will be going on there - but I believe NetApp says that 28 disks is the max for an aggregate.
I think you are referring to raid groups John, and yes when using Flexible volumes on Ontap 7.x or higher, the max raid group size is 28 or 26 data and 2 parity (RAID-DP).
You can certainly increase the aggregate past 28 drives however you will be using 2 additional parity drives and an additional raid group. Here is a good overview of aggregate/volume/qtree setup:
http://now.netapp.com/NOW/knowledge/docs/ontap/rel712/html/ontap/ mgmtsag/2qset2.htm
So, question is - anyone out there using more than 28 (like 42 !)
Yes, we have very large aggregates in use spanning many shelves :)
disks in an aggregate ? Is it possible ? recommended ? I thought that the more disks the better in an aggregate for performance reasons, but I thought I'd see what you all say !
The more spindles allocated the better for the most part, be beware of loop layout, LUN/Qtree and volume layout. Open a case with NetApp if you want to get into the nitty gritty with respect to your specific requirements and needs.
Max RAID group size is 28 disks for FC drives, 16 for SATA
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Shane Garoutte Sent: Thursday, April 05, 2007 12:49 PM To: John Foley Cc: toasters@mathworks.com Subject: Re: number of disks in an aggregate ?
On Apr 5, 2007, at 11:29 AM, John Foley wrote:
new data that will be going on there - but I believe NetApp says that 28 disks is the max for an aggregate.
I think you are referring to raid groups John, and yes when using Flexible volumes on Ontap 7.x or higher, the max raid group size is 28 or 26 data and 2 parity (RAID-DP).
You can certainly increase the aggregate past 28 drives however you will be using 2 additional parity drives and an additional raid group. Here is a good overview of aggregate/volume/qtree setup:
http://now.netapp.com/NOW/knowledge/docs/ontap/rel712/html/ontap/ mgmtsag/2qset2.htm
So, question is - anyone out there using more than 28 (like 42 !)
Yes, we have very large aggregates in use spanning many shelves :)
disks in an aggregate ? Is it possible ? recommended ? I thought that the more disks the better in an aggregate for performance reasons, but I thought I'd see what you all say !
The more spindles allocated the better for the most part, be beware of loop layout, LUN/Qtree and volume layout. Open a case with NetApp if you want to get into the nitty gritty with respect to your specific requirements and needs.
Thanks to all for the replies. A bit of a summary...
- yes, I was confusing the raid info with the aggregate info - thanks for setting me straight.
- thanks for the link to the config guides. Although I knew that the 825 could only handle 2TB, I had completely spaced that limitation while thinking about this, so that will definitely come into play here !
John
Langdon, Laughlin T. (Lock) wrote:
Max RAID group size is 28 disks for FC drives, 16 for SATA
Darren Soothill wrote:
I think you are getting confused between raid groups and aggregates.
An aggregate can be made up of lots of raid groups.
The reccomendation from netapp is not to go beyond 16 disks in a raid group every extra disk halfs the mtbf and
increases the likely hood of a double disk failure and loosing all your data.
An aggregate can be made up of lots of raid groups upto the maximum size of 16TB
Shane Garoutte wrote:
On Apr 5, 2007, at 11:29 AM, John Foley wrote:
new data that will be going on there - but I believe NetApp says that 28 disks is the max for an aggregate.
I think you are referring to raid groups John, and yes when using Flexible volumes on Ontap 7.x or higher, the max raid group size is 28 or 26 data and 2 parity (RAID-DP).
You can certainly increase the aggregate past 28 drives however you will be using 2 additional parity drives and an additional raid group. Here is a good overview of aggregate/volume/qtree setup:
http://now.netapp.com/NOW/knowledge/docs/ontap/rel712/html/ontap/mgmtsag/2qs...
The more spindles allocated the better for the most part, be beware of loop layout, LUN/Qtree and volume layout. Open a case with NetApp if you want to get into the nitty gritty with respect to your specific requirements and needs.
Jason Herring wrote:
You can have up to 28 disks in a RAID group - an aggregate can and should be bigger than one RAID group. You can have up to 16TB in an aggregate - so, you can and, by NetApp best practices (except for edge cases) should add your shelves into the aggregate up to 16TB.
Generally, the more the better is right.
Langdon, Laughlin T. (Lock) wrote:
I think the only limitation on an aggregate is the size of the aggregate. The raw max of an aggr is 17TB. So with 500 GIG drives after spares, etc you use 34 Disks. So 500 GIG ata the max aggr is 34 Disks.
With say 144GIG drives you could get 118 Disks in an aggregate.
Hope that helps
(this is on data on tap 7.2)
Skottie Miller wrote:
What size are the disk spindles ?
The limit for an f825, according to
http://now.netapp.com/NOW/knowledge/docs/hardware/NetApp/syscfg/scdot712/ind...
is 2 TB, with a 28 spindle maximum raid-DP group size.
I'm guessing your existing aggregate is made of 72G spindles, which puts it right at the 2T limit.
so, you need another aggregate, not because you hit the a spindle limit, but because you hit a maximum aggregate size limit.
The config guides are your friend.
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Shane Garoutte Sent: Thursday, April 05, 2007 12:49 PM To: John Foley Cc: toasters@mathworks.com Subject: Re: number of disks in an aggregate ?
On Apr 5, 2007, at 11:29 AM, John Foley wrote:
new data that will be going on there - but I believe NetApp says that 28 disks is the max for an aggregate.
I think you are referring to raid groups John, and yes when using Flexible volumes on Ontap 7.x or higher, the max raid group size is 28 or 26 data and 2 parity (RAID-DP).
You can certainly increase the aggregate past 28 drives however you will be using 2 additional parity drives and an additional raid group. Here is a good overview of aggregate/volume/qtree setup:
http://now.netapp.com/NOW/knowledge/docs/ontap/rel712/html/ontap/ mgmtsag/2qset2.htm
So, question is - anyone out there using more than 28 (like 42 !)
Yes, we have very large aggregates in use spanning many shelves :)
disks in an aggregate ? Is it possible ? recommended ? I thought that the more disks the better in an aggregate for performance reasons, but I thought I'd see what you all say !
The more spindles allocated the better for the most part, be beware of loop layout, LUN/Qtree and volume layout. Open a case with NetApp if you want to get into the nitty gritty with respect to your specific requirements and needs.
-
John Foley -
Langdon, Laughlin T. (Lock) -
Shane Garoutte