Skip to main content

NetApp_Insight_2020.png 

NetApp Knowledgebase

What is Auto Balance Aggregate?

Views:
332
Visibility:
Public
Votes:
0
Category:
ontap-9
Specialty:
core
Last Updated:

 

Applies to

  • ONTAP 9 
  • Clustered Data ONTAP 8.3    
     

Questions & Answers

What is Auto Balance Aggregate?

Clustered Data ONTAP provides non-disruptive volume move through CLI, as well as ZAPI.
Volume move is intended to be used by admins to move volumes around, in a non-disruptive manner, for a number of reasons, including when an aggregate starts to run out of space.

Traditionally, monitoring and reacting to low space conditions has been the responsibility of the system administrator.
The Auto Balance Aggregate (ABA) feature from Data ONTAP 8.3 and later takes first steps in an effort to automate this workflow by notifying the system administrator when it is time to move the volumes between the aggregates.
When enabled, the Balancer will continuously monitor the free space of aggregates and take action when it crosses a configurable threshold.

In the current shipping releases starting with Data ONTAP 8.3:

  1. By default, the ABA will be disabled.
  2. By default, all aggregates will be opted out.
    Customers will have to opt-in aggregates to be monitored by the balancer.
  3. When enabled, it will default to a recommendation mode. It will not initiate moves; instead, it will generate a list of recommended moves.
  4. It is recommended to use only the 'recommend' mode in the current shipping releases for ABA.
  5. All of the information stored by the Balancer will be in-core and not persistent. After any reset of the management gateway process, the Balancer will need to reconstruct and initialize any data it had been using. 
Aggregate and Volume Selection Rules:

All healthy SFO aggregates and their Flexible volumes are eligible for autobalance aggregate.

An Aggregate will not be selected if one or more of the following conditions are true:

  1. The Aggregate is unhealthy
  2. The Aggregate is partitioned
  3. The Aggregate is in mirror relationship
  4. The Aggregate is a CFO aggregate

A Flexible Volume will not be selected if one or more of the following conditions are true:

  1. It is involved in a SnapMirror relationship
  2. It is either a clone or has clones
  3. Has been moved within the last 48 hours
  4. Has exceeded a threshold of 100 IOPS (diag option volume-activity-threshold)
  5. Has exceeded the above IOPS threshold in the last 24 hours (diag option volume-inactive-delay-threshold)
  6. Is Cserver Metadata volume

Note: When you enable the autobalance feature on an aggregate, the feature will automatically be enabled for all volumes residing on it. The user can disable the feature on a per-volume basis by running the following command:

cluster_name::*> vol modify -volume <volume_name> -is-autobalance-eligible false
 

Note: Infinite volumes are excluded as they can be balanced using the Auto Balance Volume feature. 

How to enable the aggregate autobalance:


cluster-us1::> set advanced

Warning: These advanced commands are potentially dangerous; use them only when
         directed to do so by NetApp personnel.
Do you want to continue? {y|n}: y

cluster-us1::*>
cluster-us1::*> autobalance aggregate config modify -is-enabled true -aggregate-unbalanced-threshold-percent 70 -aggregate-available-threshold-percent 40
cluster-us1::*>
cluster-us1::*> autobalance aggregate config show
                 Is the Auto Balance Aggregate Feature Enabled: true
         Threshold When Aggregate Is Considered Unbalanced (%): 70
           Threshold When Aggregate Is Considered Balanced (%): 40

cluster-us1::*>
 

How to create an aggregate with autobalance enabled:


cluster-us1::*> aggr create -aggregate adb_aggr1 -diskcount 12 -is-autobalance-eligible true -node cluster-us1-01

How to enable autobalance on an already existing aggregate:


cluster-us1::*> aggr modify -aggregate adb_aggr3 -is-autobalance-eligible true

How to check the autobalance state of the aggregates:


cluster-us1::*> autobalance aggregate show-aggregate-state
                      Aggregate: aggr0
                     Total Size: 753.2GB
                      Used Size: 718.5GB
                  Outgoing Size: 0B
                  Incoming Size: 0B
 Aggregate Used Space Threshold: 527.2GB
                      RAID Type: raid_dp
                Home Cluster ID: b6044cc9-71e4-11e5-b2a3-00a09873b152
                     Attributes: CFO
                                 Excluded
                                 Mroot

                      Aggregate: adb_aggr1
                     Total Size: 224.1GB
                      Used Size: 147.GB
                  Outgoing Size: 0B
                  Incoming Size: 0B
 Aggregate Used Space Threshold: 156.9GB
                      RAID Type: raid_dp
                Home Cluster ID: b6044cc9-71e4-11e5-b2a3-00a09873b152
                     Attributes: Balancer Eligible
                                 Target For Balancing

                      Aggregate: adb_aggr3
                     Total Size: 224.1GB
                      Used Size: 160GB
                  Outgoing Size: 0B
                  Incoming Size: 0B
 Aggregate Used Space Threshold: 156.9GB
                      RAID Type: raid_dp
                Home Cluster ID: b6044cc9-71e4-11e5-b2a3-00a09873b152
                     Attributes: Balancer Eligible
                                 Target For Balancing


3 entries were displayed.

cluster-us1::*>

How to check the volume move recommendations:

The console message will be sent out when an aggregate has reached the pre-configured threshold. An EMS message similar to the following will be reported under the EMS log:

Fri Oct 16 11:39:27 UTC [cluster-us1: mgwd: mgmt.aba.move.unbalanced:info]: Auto Balance Aggregate has detected that aggregate adb_aggr1 has exceeded the threshold of 118325182509056. The aggregate currently shows a usage of 109960713981952.
 

Additionally, run the following commands to verify it manually:

cluster-us1::*> volume move recommend show
(volume move recommend show)

                                            Source        Src%     Destination     Dst %
Vserver     Volume      Time Stamp          Aggregate     After    Aggregate       After
----------- ----------- -----------------   -----------   -----    -----------     -----
vs0         volA         3/2/2013 21:11:00    adb_aggr1     35     adb_aggr3         35
1 entries were displayed.

cluster-us1::*> autobalance aggregate show-unbalanced-volume-state

               Last Checked On: 9/29/2015 15:40:20

                        Volume: volA
                     Footprint: 20.20MB
 Last Time Over IOPS Threshold: -
                   Last Placed: 9/28/2015 14:18:15
                    Attributes: Ready

                        Volume: test                                           
                     Footprint: 20.20MB                                        
 Last Time Over IOPS Threshold: 9/12/2015 16:20:18                             
                   Last Placed: 9/11/2015 10:16:42                             
                    Attributes: Over IOPS Threshold                            
                                In Mirror                                      
                                Stabilizing                                    
                  

cluster-us1::*>

Additional Information

Related Link
ONTAP 9.x: autobalance aggregate config commands