SupportBDBC
Contributor
Contributor

VMWare iSCSI DVSwitch

Hi All,

I was wondering the best way to configure iSCSI for windows initiator.

We have a DVSwitch with multiple port all bound to individual nics and assigned to the software initiator on the host. this is how we connect our LUNS. For the VM's how should we attach extra drives, by the host initiator or VM initiator? If we do it by the VM i assume we have to have multiple iSCSI nics on the VM and load balance that way otherwise you will only access one nic and have no redundancy?

Thanks

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5 Replies
erikverbruggen
Hot Shot
Hot Shot

Do you have any requirement why you want to use in guest iSCSI connections instead of just presenting a VMDK from a datastore?

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SupportBDBC
Contributor
Contributor

Anything as a secondary drive to the OS drive over 300gb is generally not put as a VMDK as it can make vMotion troublesome if we don't have enough space on other datastores. (our file server has over 8TB of storage applied to it over various luns.

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VMARA
Enthusiast
Enthusiast

I believe you need to connect to an iSCSI target to get a additional disk to your VM, as long as you can connect to the target you can create a separate iSCSI disk from your windows iSCSI initiator. It's nothing to do with the dvSwitches. If you need to have a separate iSCSI datastore and multipathing for your datastore is a different scenario. Not sure what is the scenario that you need

Read multipathing over iSCSI in my blog post: iSCSI Multi Pathing in VMware ~ TECHCRUMBLE

Aruna Lakmal Virtualization Professional | vExpert and a Blogger
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erikverbruggen
Hot Shot
Hot Shot

It does have something to do with your dvSwitch but this all depends if you want to use multipathing from the OS. The whole idea of iSCSI multipath is to let the iSCSI protocol handle redundancy and not the network stack. If you want to do this you have to add two nics to the vm, preferably each on a different subnet, and connect to the iSCSI target from these nics. The portgroups to which these nic's are connected should be available on a single VMNIC, just like you do with multipathing for iSCSI datastores.

There could be a prerequisite for additional software from the storage vendor on your VM if you want to use multipathing. For example, NetApp provides software (DSM) when you want to use multipathing from within the OS.

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SupportBDBC
Contributor
Contributor

This works with standard vSwitches, but you can't bundle those links on DVSwitches if they are also used for the hosts iscsi initiator, or do i need a third DVSwitch running LACP?

We can already connect to the iSCSI disk from Windows, but it will only ever utilize one nic on the DVSwitch, therefore giving no redundancy.

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