Newbie Q - iSCSI and ESX IP address

[jatdesi]

Hi - I'm evaluating ESX and am in the process of setting it up with iSCSI storage. My question is regarding usage of IP addresses: The ESX server in my case has 2 NICs. A default install of ESX creates a vSwitch0 (consisting of a Service Console using the ESX server's IP address AND a VM Network port group). From what I understand, when using iSCSI, I enable the second NIC on the ESX box, assign it a new IP for the VMkernel services AND create another Service Console port with a third IP. This basically implies I will need 3 IPs for a single ESX box to talk to an iSCSI storage area. Is this the correct way to implement ESX and iSCSI i.e. do I need 2 Service Console ports at different IPs? Any help/guidance is appreciated.

[oreeh]

You only need the second COS connection if your iSCSI storage is on a dedicated subnet / isolated from the rest of the network (strongly recommended).

[aguacero]

Oreeh is on the money! You create the second COS for security purposes and to separate the iSCSI traffic to talk exclusively with the iSCSI San.

If you found this information useful, please consider awarding points for "Correct" or "Helpful". Thanks!!!

[quadshop]

Scenario 1: You are doing this for evaluation only, and your iSCSI SAN is accessible from the subnet where you have your service console. You do not have a hardware iSCSI host adapter, so are using the software one built in to ESX server.

In this case, you do not need a second service console, as the original one can do the parts of iSCSI done via the service console port.

Scenario 2: You are doing this for evaluation or production, and your "primary" service console is on a subnet different from your iSCSI SAN. You do not have a hardware iSCSI host adapter, so are using the software one built in to ESX server.

In this case, you need an IP for your "original" service console, PLUS...

On the dedicated IP subnet where your iSCSI SAN resides (probably a 192.168.0.0 or a 10.0.0.0 address) you will need two IP addresses assigned, one for the iSCSI adapter, and one for a second service console. The service console on the iSCSI SAN network is needed (I believe) to do service discovery, and so needs to be on the same IP network as the iSCSI adapter.

If you want to play with the multipath features of ESX (at least with the software HBA), then you have to have multiple subnets. You will end up having even more service consoles, as each subnet will need a service console with its own IP address.

This may or may not be the case with hardware iSCSI adapters. But since you are only talking about NICs, I assume you are using the software adapter.

[jatdesi]

Thanks for your replies. Since I am currently working to evaluate ESX, I have to use a single subnet. I am using the iSCSI initiator built into VMkernel (basically following Scenario 1). As such, I will use one NIC on the ESX host for Service Console and the other for iSCSI.