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Aggregates and Disk Raid Groups

I'm looking for a document on how to setup aggregates and disk raid groups.  Specifically I saw posted somewhere, and someone also mentioned it to me this week, that when their aggregate ran out of space and already had the max number of disks assigned to the raid group they had to go in and manually create a new raid group and assign it to the aggregate.  Does this sound correct, I thought I read somewhere that the netapp filers handle the creation of raid groups automatically but I'm not sure.  Any clarification and examples on this matter would be greatly appreciated. 

Aggregates and Disk Raid Groups

Let's say for example you create a 14 disk aggregate with raidsize set to 14, when the aggregate gets full and you add more disks to the aggregate the next raid group will automatically be created. Bear in mind that the minimum number of disks for a RAID DP raid group is 3 and for a RAID 4 raid group is 2.

Check out the Storage Management Guide for more info:

https://now.netapp.com/NOW/knowledge/docs/ontap/rel7351/html/ontap/smg/index.html

Aggregates and Disk Raid Groups

So let's take that example you have:

I create a 14 disk aggregate with a raid size of 14 using the following command:

aggr create aggr1 raid_dp -r 14

So I now have aggr1 created using 14 available disk with raiddp in rg0 (raid group 0). I then go and add a new disk shelf and want to grow my aggragate because I'm running low on space. 

Do I do this?:

aggr add aggr1 4@1000 to automatically create a new rg1 (raid group 1) made up of 4 1TB drives

or

aggr add aggr1 -g rg1 4@1000 to create the new rg1 (raid group 1). 

______________________

(Can below even be done)

Let say rg0 isn't full but I want to create a new raid group rg1 and start adding disk to it for aggragate1

Would you be able to just add a new disk shelf and do:

aggr add aggr1 -g rg1 4@1000 to create the new rg1 of 4 1TB disks and add it to aggragate1?

Then go back and add specific disk to fill rg0

BTW GREAT document link

Aggregates and Disk Raid Groups

Data Ontap does most of the work for you so you don't need to specify rg1 as the name of the next raid group, if your existing raid group is at the size specified in raidsize and you issue `aggr add` it will automatically create the next raid group with the number of disks you specify.

If raidsize is set to 14 and you want to create a new raid group before the first one is fully populated you would change the raidsize value to the current number of disks in the raid group. You would then issue `aggr add` and the new raid group will be created. Once that's done you could set raidsize back to 14 again if you wanted.

Re: Aggregates and Disk Raid Groups

Sorry to hijack the thread, but I have a similiar question about RAID Groups and Aggregates and didn't want to spawn a new thread.

I am new to the NetApp world and am coming over from the "other" storage vendor and the company I work for just ordered a FAS2040 unit with a DS4243 fully populated drive shelf. I have been reading through several of the NetApp documents and have seen the discussion of RAID Groups, Aggregates, and best practices come up a few times. Below is our planned setup of the disks when we receive the unit:

11 x 1 TB + 1 HSP for the first aggregate (drives in the FAS2040 "main" unit)

22 x 300GB + 2 HSP for the second aggregate (DS4243 shelf)

So from the reading I have gathered we would want to change the default RAID Group size from 15 to a size of 11? My reasoning behind that would be is stated on page 101 of the Storage Management Guide it says:

"Strorage system performance is optimized when all RAID groups are full."

Any thoughts or comments are greatly appreciated as I am hoping that I am understanding this correctly.

TIA

-Jason

Re: Aggregates and Disk Raid Groups

Hi,

A very good material about it is the FAQ maintened by Jay White available at Field Portal: https://fieldportal.netapp.com/viewcontent.asp?qv=1&docid=9866

It is a very interesting FAQ talking about the new Shelves, SAS disks and how to create aggregates tuning the Raid Group Size option.

See you,

Nasc

NetApp - Enjoy it!

Aggregates and Disk Raid Groups

Rodrigo Nascimento wrote:

Hi,

A very good material about it is the FAQ maintened by Jay White available at Field Portal: https://fieldportal.netapp.com/viewcontent.asp?qv=1&docid=9866

It is a very interesting FAQ talking about the new Shelves, SAS disks and how to create aggregates tuning the Raid Group Size option.

See you,

Nasc

NetApp - Enjoy it!

Rodrigo - Thank you for the link. Once I get my unit and register it towards my NOW account I will give it a read.

-Jason