PowerStore iSCSI ESXi

Hello all_rights_reserved,

Which Powerstore model do you have a powerstore T or X? Here is a link to Networking Guide for PowerStore T Models, as well as Networking Guide for PowerStore X Models, which has the worksheets for how best to configure your iSCSI network.

https://dell.to/4atBcZu

https://dell.to/3xpr8BV

Hello,

i think the better guide is the https://elabnavigator.dell.com/vault/pdf/VMwareESX.pdf?key=1588943108041 one because OP asks for vSphere ESXi iSCSI.

Notes:  PowerStore OS 1.x only supports "Single Subnet(VLAN)) for iSCSI and with PowerStore OS => 2.x they support Single and Multi Subnet configurations and they named the MultiSubnet the preferred solution.

Regards,
Joerg

"...with PowerStore OS => 2.x they support Single and Multi Subnet configurations and they named the MultiSubnet the preferred solution.."

But... Why? I am bringing in a PowerStore into our datacenter where we have multiple VMware hosts with FOUR iSCSI vmnic ports each, all of which are in a single subnet and vswitch, and mapped one to one to a single vmkernel port (overriding failover).

My questions are as follows: 

1. As a Best Practice, what benefit does splitting the ports into separate subnets provide?

2. What are the downsides to having multiple dedicated vmnic/vmkernel pairs on the same dedicated non-routable iSCSI VLAN/subnet?

3. IF there is a compelling reason and we decide to convert our storage infrastructure to a MultiSubnet iSCSI one would it be advisable to have an separate iSCSI-A and iSCSI-B... or to go whole hog with iSCSI-A, B, C, and D subnets?

Thanks for the consideration!

Hi,

Thanks for your question.

I couldn’t find any recent documentation on the reason why. Separating subnets allows for multiple vmkernel ports to be used. https://dell.to/3ZbHt95 and

https://dell.to/3yZLwuK

Let us know if you have any additional questions.

I currently have 6 hosts, each with 4 iSCSI vmkernels on a single vSwitch, and all of them on the same subnet with no issues. I just have each vmkernel port mapped to a single vmnic on that host. this allows multipathing with no issues.

I will look at the links you posted, but I am still confused as the rationale.

For clarity, I am adding the following picture:

in this case vmk5 maps ONLY to vmnic4, etc...

Im just guessing.  The Powerstore replace a lot of Compellents which are Multi-Subnet* and an ESXi Hosts only supports one type of swISCSI setup (Binding or Non-binding) per time.

* An Compellent can also setup as a Single Subnet but that was only supportet when a customer migrates from EqualLogic.

@Sigil_Thane 

yes you can setup iSCSI-A,B,C,D Subnets.  I have my doubt that 4x25G is needed and that there is a different compared to just 2x25G but i dont know anything about your environment. Btw... we switch from using  IO Modules to Mezz Ports and use the default Bond0 now for our iSCSI Storage Network.

Did you consider to use NVMe/TCP instead of iSCSI.

Yes i found that Dell makes a "bad" Job when its comming to the documentation about PowerStore and connecting Hosts. The Information is spread about single documents and there is not a single example for a standard setup with 2xSubnet, Dual Switch and ESXi with 2 Ports.

Regards,
Joerg

@Origin3k​ We are not currently using NVMe/TCP simply because the Compellent SANs we have are RAIDed HDDs instead of SSD or NVMe...

Additionally, we will be supplementing, instead of replacing, our existing Compellent SANs with the PowerStore hardware (Tiered Storage FTW)