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iSCSI Data Services IP Address - Can use different IP subnet than the CVM's subnet?

  • April 28, 2025
  • 5 replies
  • 139 views

Hello Team,

One of our customer have a requirement to use a different subnet for Nutanix Volume iSCSI IP address than the CVM IP subnet range. 

This is because he wants the iSCSI volume traffic not to flow via his firewall. So he intent to use IP subnet for iSCSI Volume same as the VM (iSCSI Initiator) range. 

Going by the documentation https://portal.nutanix.com/page/documents/details?targetId=Volumes-Guide:vol-volumes-external-ip-address-c.html, it states: 

“This IP address should be in the same subnet as the cluster Controller VM IP eth0 network interface addresses”

Is this a mandatory requirement? 

Thank you in advance!

This topic has been closed for replies.

5 replies

JeroenTielen
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  • Vanguard
  • 1770 replies
  • April 28, 2025

Hi Ravi, 

 

Yes that is mandatory. But if the virtual machine is in the same cluster as where the volume group comes from then you can directly attach the volume group and you don't have to configure the iSCSI in the virtual machine. 

Steps to do so:

 

  1. Create a volume group with the required disks and sizes. 
  2. Save the volume group
  3. Update the volume group and attach VM(s) to it.

 


  • Author
  • Adventurer
  • 3 replies
  • April 29, 2025

Hello ​@JeroenTielen,

Thank you for your quick response. 

The use case for the Nutanix Volume Group is for Veritas InfoSclae cluster requirement - which needs a shared storage presented to both cluster VMs. 

I forgot to mention - This is not Nutanix AHV setup but this is Nutanix ESXi setup, is this option still valid?

If it is valid, the volume group traffic with contain within the cluster and wont be going outside cluster I believe (customer’s firewall). 


JeroenTielen
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  • Vanguard
  • 1770 replies
  • April 29, 2025

I dont have a Nutanix ESX environment up and running at the moment (they are getting more and more being replaced by AHV). But I suspect it is possible. But it is an easy test. Create the volume group and attach the vm to it. 


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  • Adventurer
  • 7 replies
  • April 29, 2025

@Ravi Kumar 

You should read “Securing Traffic Through Network Segmentation” and especially “Service-Specific Traffic Isolation” chapter
https://portal.nutanix.com/page/documents/details?targetId=Nutanix-Security-Guide-v7_0:wc-network-segmentation-intro-wc-c.html
 

You can split MGMT and ISCSI traffic (ESX or AHV) :
 

 


  • Author
  • Adventurer
  • 3 replies
  • May 9, 2025

Thank you ​@JeroenTielen  & ​@marcrousseau !

We are planning to go with two options as of now.

Option 1: Use direct attachments of VM to Volume Group

 

 

Option 2: We can have secondary NICs assigned to the VMs in the same range of iSCSI IP, so the communication doesn’t have to go through the firewall.

Yet to implement the action, will keep this thread updated with the results.