ONTAP Discussions

Any way to find out which IP being used in a NFS mount using DNS name load balancing

netappmagic
4,195 Views

We use an external DNS load balancing to balance the load amount LIF's. in /etc/fstab file, we use name.doamin.com to reference NFS server. Any way can I find out what IP currently this name.domain.com is using, and to mount the NFS volume?

 

Thank you!

7 REPLIES 7

GidonMarcus
4,086 Views

Hi

 

I think that netstat will have your requested data, either on the host or on the filer  (Using: node run -node * netstat   - careful. likelly a long output. increase terminal buffer).

 

Coulden't find a better methood

 

Gidi

Gidi Marcus (Linkedin) - Storage and Microsoft technologies consultant - Hydro IT LTD - UK

heightsnj
3,784 Views

I have same question here.

 

I tried the command suggested, netstat(without any options) on both filer and clients. It only shows me the DNS name for SVM, not particular LIF the client currently is using to mount the NFS. Under DNS round-robin policy, LIF could be different in different mounts. 

 

How do I find which LIF a client is currently using to mount a NFS volume?

GidonMarcus
3,775 Views

Hi @heightsnj

 

Will

node run -node * "netstat -I a0a-321"

work for you?

 

without the -I itl show's you the LIF address.  so i guess you can just filter it in excel / notepad ++

 

Gidi

Gidi Marcus (Linkedin) - Storage and Microsoft technologies consultant - Hydro IT LTD - UK

GidonMarcus
3,774 Views

sorry - just re-read it. you want the mount assignment per IP?

i think (didn't tested it) - that because NFS is stateless. nothing will cache the DNS name beyond the TTL. so the communication will not be persistent on the same IP.... real life can be different. but that's what i assume....

Gidi Marcus (Linkedin) - Storage and Microsoft technologies consultant - Hydro IT LTD - UK

heightsnj
3,772 Views

I probably didn't make it clear. let me try it again:

Due to DNS round-robin policy name, every time when I mount a NFS volume, the filier's IP might be different. So, I wanted to find out what filer's IP is current mount using?

unless I remount or reboot the client, the client should talk to NFS volume using the same filer's IP.

 

 

Senza21
3,694 Views

With the following command you can at least see how many connections are made through a specific LIF, perhaps this helps?

network connections active show-lifs -vserver your_vserver -lif *

 

Or try the:

network connections active show-clients -vserver your_vserver

Could perhaps make this an ssh session to the cluster where you grep the node and your IP?

 

 

heightsnj
3,678 Views

Unfortunately, both could not show the information I am looking for. 

 

network connections active show-lifs -vserver your_vserver -lif *

very limited information provided by this command, only shows you the count of howmany active connections

 

 

network connections active show-clients -vserver your_vserver

List all clients, and the vserver name.

 

Again, I am looking for the vserver's IP currently being used by a particular mount on the client. 

 

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