iSCSI on LACP configuration

[slavonac]

HI

We have esxi 7.03 and will use iSCSI on standard switch. Dell doesnt recomment using ports in LACP for their storage since iSCSI already has MPIO

Anyone has iSCSI with LACP connections several articles are against that 

https://core.vmware.com/blog/iscsi-and-laglacp

https://kb.vmware.com/s/article/1001938

[markey165]

@slavonac - As you rightly point out, the KB specifically states:

• LACP is not supported for software iSCSI multipathing.

Note also that you mention are using a Standard Switch, and the KB also points out that "ESXi supports LACP on vDS (ie Distributed Switch) only"

In summary, to remain properly supported, LACP should be removed from the switch configuration of your iSCSI connections.

HTH

[slavonac]

The reason I ask is that we have Dell Power Store T storage and first 2 ports on embedded card form LACP bond instantly

I told my network guy not to use these but use IO module ports and forward iSCSI traffic to those

The way it is configured now we have iSCSI going through LACP bond on the network switch and storage but I was against that

[markey165]

Apologies if i'm missing something, but you are referring to 2 different endpoints. Whilst your Dell Powerstore may well auto configure LACP at the storage end, it doesn't mean you need to configure LACP at the ESXi host end. It isn't like Jumbo Frames where the MTU needs to be configured to be same on every link between endpoints.

Unless i'm missing something, the advice remains the same in that you should disable LACP on the Host end for the iSCSI connections.

HTH

[slavonac]

well LACP can only be configured as far as i know on vDS and not on standard switch however based on these articles and this one

https://wahlnetwork.com/2014/03/25/avoid-lacp-iscsi-port-binding-multi-nic-vmotion/

LACP had to be configured on Network switch because when Dell powerstore is on these ports are automatically in LAG

BUt some people say that LAG shouldnt be used since iSCSI already has load balancing MPIO so LACP will not have any benefits but it can cause issues

[SidneyStephens]

Thank you for the link, you made my day.

[VadaBass]

Thank you so much for the article.