VMware Solutions Discussions

How many aggregates per controllers


What is the best practice on creating an aggregate. Only one per controller ?

Can I have one aggregate with SAS 600GB 12 Drives and another aggregate with SATA 2TB 12 Drives on the same Controller?

Version 8.1.1 7-Mode Fas2040


Re: How many aggregates per controllers


I have the same questions. I could not find good answers by searching Netapp Documents.

1)I noticed we had some spare disks that are not in aggregates, not sure it is done on the purpose or human error

2) It looks like you only can aggregate same model of hard disks such as SATA or SAS, right?

3) Do we need to use Qtree? I saw demo video form netapp to create agggregate first then create qTree but we don't have qTree in the real environment

Re: How many aggregates per controllers


Ok I think I can help you.

1. Best Practice You need 1 Spare disk per aggregate in case of you need extra space for an emergency or a Disk die. you can add the spare disk to the aggregate and use it wile you fix the problem once added you can't remove it.

2. Yes, and about the space it you add a SAS 600 GB disk  to a SAS 300 GB disks aggregate you will only be able to use the 300 GB of that Disk.

3. No you don't need to use Qtree.

On my side I need to practice with Qtrees more...

Re: How many aggregates per controllers


I agree with this answer.

You can also mix, in the same aggregate fc and sas disk (but a fc disk cannot be a spare for the sas disk).

As Jose says, you should put in the same aggregate disks with the same speed and size!

Re: How many aggregates per controllers


Joe and Nicolas: your guys know more than me for sure :

1) How do I know our NAS is suing fc or iscsi? It is in remote location so I only can see in the netapp manager conosle.

2) If I add a new ESXi host to the existing esxi cluster and nas storage, What I need to do on NetApp side? I saw all other existing hosts mounted to all datastores

3) Do I need to manually mount the new host to all exsiting NAS volumes? How? if it is not auto-detected?

Re: How many aggregates per controllers


You need at least one spare per disk type per controller, so one SAS and one SATA. So if you have SAS and SATA aggregates on the same controller, you would need at least two spares.

Re: How many aggregates per controllers


Any one knows the answer to my question?

Re: How many aggregates per controllers


The number of aggregates is not limited by the controller model on 7-mode.  There is a disk count limit that determines the maximum number of disks that you can connect to a controller.  On the FAS2040 with Data ONTAP 8.1.1 7-mode, there is a 136 disk limit. 

You can create a 12 disk SAS aggregate and a 12 disk SATA aggregate without issue on the same controller.  With the FAS2040, you can mix SAS & SATA external disk shelves on the same disk stack provided that you only have 1 transition in the stack between the SAS shelves & the SATA shelves.   The disks in your aggregate should be the same disk speed & disk type (i.e. an aggregate with all 10K SAS disks, an aggregate with all 15K SAS disks, an aggregate with all 7.2K SATA disks).  You can mix disks of different sizes in the same aggregate provided that they are a) the same disk type (i.e. SAS or SATA) and b) the different disk sizes are in separate RAID groups.  For example, I could mix 600GB SAS disks & 900GB SAS disks in the same aggregate, but I would want the 900GB disks to be in a separate RAID Group(s) from the 600GB disks.   For ease of management, most customers work on the premise that the aggregates should contain disks of the same size. 

As for disk spares, at a basic level, you need at least 1 spare disk of each disk type & disk size assigned to each controller.  If you have, for example, 600GB SAS disks & 2TB SATA disks that are assigned to "ControllerA", then there needs to be at least 1 600GB SAS disk and 1 2TB SATA disk assigned to "ControllerA" as spares (spare disk is one that is not allocated to an aggregate). 

Hope this helps with your original question!


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