Category Archives: Clustered Data ONTAP

Display “big talkers” clients on cDOT

It is a common request from customer that wants to know who are the most active clients to a system. Though not hard to obtain, there is no obvious menu that lets you do that, so there it is :

First of all, you need to be in advanced mode and start statistics collection for the “client” object :

netapptest2::*> 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

netapptest2::*> statistics start -object client
Then you let it run for some time, and you can start looking at who the most active clients are :
 netapptest2::*> statistics show -object client -instance !Cluster* -sort-key nfs3_ops -counter nfs3_ops -tab

ntap2_vs1: client: 5/31/2016 23:59:26

instance nfs3
 name ops
 ---------------------- ----
 ntap2_vs1:10.20.245.11 31
 ntap2_vs1:10.20.45.95 0
 ntap2_vs1:10.20.45.67 0
 ntap2_vs1:10.20.45.60 0
 ntap2_vs1:10.20.45.58 0
 ntap2_vs1:10.20.45.43 0
 ntap2_vs1:10.20.45.40 0
 ntap2_vs1:10.20.45.39 0
 ntap2_vs1:10.20.45.37 0
 ntap2_vs1:10.20.45.33 0
 ntap2_vs1:10.20.45.235 0
 ntap2_vs1:10.20.45.234 0
 ntap2_vs1:10.20.45.226 0
 ntap2_vs1:10.20.45.225 0
 ntap2_vs1:10.20.45.223 0
 ntap2_vs1:10.20.45.221 0
 ntap2_vs1:10.20.45.218 0
 ntap2_vs1:10.20.45.195 0
 ntap2_vs1:10.20.45.19 0
 ntap2_vs1:10.20.45.183 0
 ntap2_vs1:10.20.45.18 0
 ntap2_vs1:10.20.45.158 0
 ntap2_vs1:10.20.45.157 0
 ntap2_vs1:10.20.45.156 0
 ntap2_vs1:10.20.45.134 0
 ntap2_vs1:10.20.45.133 0
 ntap2_vs1:10.20.45.132 0
 ntap2_vs1:10.20.45.124 0
 ntap2_vs1:10.20.45.120 0
 ntap2_vs1:10.20.45.118 0
 ntap2_vs1:10.20.45.114 0
 ntap2_vs1:10.20.45.113 0
 ntap2_vs1:10.20.45.108 0
 ntap2_vs1:10.20.45.100 0
 34 entries were displayed.

You can use another field instead of nfs3_ops, just use “?” character to get a list of available fields when you get to that part of the command line.

Here are the options available at this time, you can also use multiple fields by using a comma “,” separator.

  cifs_ops                    
  cifs_read_ops               
  cifs_read_size              
  cifs_write_ops              
  cifs_write_size             
  instance_name               
  instance_uuid               
  local_ops                   
  mount_ops                   
  nfs2_ops                    
  nfs3_ops                    
  nfs4_ops                    
  node_name                   
  node_uuid                   
  process_name                
  remote_ops                  
  rx_data                     
  rx_packets                  
  total_ops                   
  tx_data                     
  tx_packets                  
  vserver_id                  
  vserver_name

Snapmirror data from 7-mode to Clustered Data ONTAP [Screencast]

In this screencast I will show you how to migrate your data from a 7-mode system to a Clustered Data ONTAP system without using add-on software.

Note that I strongly encourage using 7MTT tool but if for some reasons, you want to do that manually, here is how.

In this video, you will see :

  • How to create the destination SVM
  • How to create the destination volume
  • How to establish a peer relationship
  • How to create the snapmirror relationship
  • How to do the cutover

Serve DNS load balancing IPs on a non data network

[EDIT] Please use caution when setting up your environment according to this article. In some case, especially when using BIND DNS server with non-default parameters, you may end-up with requests going to data LIF even if they are on the storage network and you set “-listen-for-dns-query false” on it.

I got an interesting question from a customer about the way DNS load balancing is served in a cluster.

For network topology reasons, they needed to serve DNS requests on a network different from the data network used by the clients to access storage.

The problem is that Data ONTAP only listens to DNS requests on data LIFs that has been configured for DNS load balancing. The obvious issue is that if you configure an additional LIF on the management network, the load balancer will start serving this IP to the clients, which might not be the optimum path or even not routed at all.

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