Adding physical network adapters to hosts in a vsan -

[whutchis]

I have a cluster of VxRails that are currently running on a single switch.   We want to add a 2nd switch, and connect the two additional NICs for each host.   Is there any issue adding the new uplinks to the existing VSAN?

[TheBobkin · Accepted solution]

Hello whutchis@bucknell

Welcome to Communities,

Having redundant switch-links is of course advised, but do note the following:

- If you are going to go with multiple vSAN vmkernel ports then they need to be on different subnets from one another (and obviously from all other traffic too as multihoming is unsupported and can cause issues).

- Active/Standby of the vmnics attached to each vmk (in my opinion) is preferable and functions best.

- As with any major network change - schedule down-time if possible unless you are 100% confident you are not going to cause an outage (and or can tolerate one). Sure you could do one node at a time with FDM/EA Maintenance Mode but you need to be positive your validation of the network is solid before taking these hosts out of MM.

Myles has some great points and details relating to the above here:

https://blah.cloud/infrastructure/migrating-vsan-vmkernel-ports-new-subnet/

Bob

[sk84]

TheBobkin is right.

Basically, that's not a problem. To be on the safe side I would also recommend to put the host in the MM and configure the 2nd adapter as standby or unused adapter, check the cabling and switchport configuration and only when everything is correct let it on standby or switch to active, depending on what you have in mind.

However, if you have multiple vmknics with different VLANs for vSAN, there may be an IO delay between 10 - 90 seconds if one of the two uplinks is not working properly.

See: Configuration 2