VMware Cloud Community
THP
Contributor
Contributor
Jump to solution

Running Software iSCSI over a different subnet from the Management traffic

I'm hoping that I am missing something obvious that you smart folks might be able to help with.

I am in the process of setting up a small instance of vSphere using ESXi 4.0 Update 2 and unlike most of our environment we are using iSCSI storage rather than fibre SAN.

The intent is to set up one network on subnet A for management and Vmotion traffic which will have 2 pNICs attached.

We have a second subnet 'B' allocated for the iSCSI storage and have 2 seperate pNICs which will be set up across two vSwitches, 1 pNIC to each.

We set up the Management/vmotion switch on one subnet and obviously input the default gateway for that subnet when asked.

Naturally the iSCSI subnet has a different gateway and so when I entered the correct IP on Subnet B into the Kernel port it still appears to be trying to route through the gateway for Subnet A leading to storage not being visible.

We have verified that the problem is not with the storage or the ESXi set up by proving that if we give the iSCSI ports IPs from Subnet A (and also the storage) then we can see the storage with no problems - the issue simply seems to be around trying to get it working on a totally isolated subnet.

The isolation of storage traffic is a customer demand and not something we can ignore.

Does anyone know if this is possible (and if so what I need to do to solve the problem) OR do we need to look to moving to ESX Classis and use it's ability to use 2 different gateways?

I feel like I must be missing something pretty obvious as I'm sure there must be a way to achieve segregation of traffic across subnets for other kernel activities like vmotion, fault tolerance and management traffic.

Reply
0 Kudos
1 Solution

Accepted Solutions
AntonVZhbankov
Immortal
Immortal
Jump to solution

There is only one gateway for VMkernel, so you can segregate VMotion / iSCSI / Fault Tolerance only if it would be non-routable subnets, i.e. all the hosts in the same subnet.


---

MCSA, MCTS Hyper-V, VCP 3/4, VMware vExpert

http://blog.vadmin.ru

EMCCAe, HPE ASE, MCITP: SA+VA, VCP 3/4/5, VMware vExpert XO (14 stars)
VMUG Russia Leader
http://t.me/beerpanda

View solution in original post

Reply
0 Kudos
4 Replies
AntonVZhbankov
Immortal
Immortal
Jump to solution

There is only one gateway for VMkernel, so you can segregate VMotion / iSCSI / Fault Tolerance only if it would be non-routable subnets, i.e. all the hosts in the same subnet.


---

MCSA, MCTS Hyper-V, VCP 3/4, VMware vExpert

http://blog.vadmin.ru

EMCCAe, HPE ASE, MCITP: SA+VA, VCP 3/4/5, VMware vExpert XO (14 stars)
VMUG Russia Leader
http://t.me/beerpanda
Reply
0 Kudos
tWiZzLeR
Enthusiast
Enthusiast
Jump to solution

THP - In vSphere 4 you only need to have the one VMkernel port which will be used for vMotion. On my network, this is on the same subnet as the Service Console (so they both have the same default gateway).

My setup sounds similar to yours in that I also have my iSCSI traffic on a seperate 192.168.x.x 'C' subnet which does not need to have a gateway defined as that traffic is non-routable.

THP
Contributor
Contributor
Jump to solution

I'm starting to see the problem - the subnet our storage is currently on is a routed network so without a gateway it's lost. I'll have to work with our network folks and see if we can get that changed.

Reply
0 Kudos
Dave_Mishchenko
Immortal
Immortal
Jump to solution

You can manange the routing on your ESXi host with vicfg-route from the vCLI.




Dave

VMware Communities User Moderator

Now available - vSphere Quick Start Guide

Do you have a system or PCI card working with VMDirectPath? Submit your specs to the Unofficial VMDirectPath HCL.

Reply
0 Kudos