iSCSI Virtual Switch configuration

[barry_byrne]

Hi All,

Am new to iSCSI and trying to figure best practice with regard to configuring the virtual switches in VMware. I've googled and searchd but can't seem to figure what is the best way to set this up.

I'm using a Dell/EMC AX-45i with two storage processors, and two separate switches.

There are four Storage Processor ports, A0, A1, B0, B1. It seems to be that two of these are active per Virtual Disk e.g. A0 & B0.

Ethernet connections are as follows - separate networks for each switch

SPA0 - Switch 1, 172.27.1.101

SPA1 - Switch 2, 172.27.2.101

SPB0 - Switch 1, 172.27.1.102

SPB1 - Switch 2, 172.27.2.102

This is as per the EMC docs. Each switch has a separate network and there's no link between them.

On the VMwareside, should I create two separate Virtual Switches? One for 172.27.1.0 and one for 172.27.2.0 with one NIC in each?

Or should I make all the SP ports be in the same network and assign two NICs to that switch? With some kind of load balancing.

I guess I'm after best performance to make use of both active ports where possible.

Appreciate any help or pointers.

Regards,

Barry

[Anders_Gregerse]

I would have both switches on the same network for simplicitys sake, but it depends on your network and the switches.

We have an iSCSI setup with a storage system from a different vendor, we have connected them to a switch stack.

[rwozniczka]

I'm assuming in your EMC AX-45i only 2 port at any time are active so while SPA0 and SPB0 are active other 2 are in passive standby mode, there is a reason why vendor recomendation is to isolate those 2 iSCSI networks from each other for failover reason so you do not want all 4 SPs on one iSCSI network although initially all might looks OK you will run into odd issues with SPx0 failing to SPx1 when both on same iSCSi network... I would say your assumption about creating multiple vSwitches or single vSwitch but with VLANS is correct, this is just my opinion

RWOZ

[barry_byrne]

Thanks to all for replying to this, and sorry for delay in answering myself.

Am still a little unsure as to best setup here.

On the vmware host, I created two virtual switches, each of which has a service console port, and one NIC which is connected to each of the two iSCSI switches. Each of the two Virtual Switches is on a diffent subnet. When I set it up this way, all four ports on the AX4-5i are listed as Active. This appears to work, but I'm not confident that it's the right way!

Previously, I tried just one subnet (same one on both switches, with each storage processor port having an IP address in the same subnet. On the VMware side, I created one Virtual Switch with two NICs. In this setup, the AX4-5i showed one port active and one port passive on each of the storage processors.

I did get the impression that the correct use of AX4-5i has one active and one passive port on each processor, so I'm a bit unsure of this.

Thanks again for any help already.

Regards,

Barry

[maxmino]

I'm interested also what is the best configuration, 2 vSwitch in different subnet or 1 vSwitch in team with 2 NIC in the same subnet (in this case the physical swicht are interconnect with uplink cable) ?

Regards,

Massimo

[rwozniczka]

as far I can tell with any iSCSI SAN working in Active/Passive configuration were Passive controller is in Standby Mode waiting for failover you should always use 2 sunbets isolated from each other so that would be 2 vswitches and different subnets, that might not be the case in Active/Active iSCSI SAN.

[Rodos]

Barry, its implied in your question but can we assume you are talking about connecting this to ESX with the software initiator. Are you also wanting to present any LUNs straight into the guest OS via the Microsoft initiator?

[barry_byrne]

Hi,

Yes I am using the software initiator to ESX. At this point I'm not intending to use MS initiator in Guest OS. So would just be a single VMFS partition on each LUN. Would that make a difference?

[dr00l]

What about having 1 vSwitch with a 2 NIC team, connected to 2 separate physical switches. Have two sets of SC/VMKernel pairs on two separate VLANS on that vSwitch. Override the vSwitch failover order on one of the SC/VMKernel pairs to utilize the vSwitches standby NIC as primary (and the vSwitches primary NIC as standby).