how to add new leaf switches to expand a running fabric using EFA

[TingY]

In guide "Extreme Fabric Automation vCenter Integration Guide Version 3.1.0", https://documentation.extremenetworks.com/efa/efa_3.1.0/vcenter/GUID-010D3E37-1D67-4275-AFBC-5246FAB...

It indicated procedure like this:
Procedure
1. Use the efa fabric device add command to add a single device. To add multiple devices in a single command, use the add-bulk option instead.
# efa fabric device add
# efa fabric device add-bulk
2. Use the efa fabric configure command with the --force option to force the fabric to update itself by removing and adding all devices that make up the fabric. When the fabric comes up again, it will include the newly added devices.
# efa fabric configure --force

Could this procedure be used for normal Extreme CLOS 3/5 stage fabric (not related with vCenter)?   
Is the "--force" mandatory in step 2?  If yes, it will impact the current service, right?

[Michael_Morey · Accepted solution]

Ting,

Yes this procedure can be used for adding an SLX to the fabric.

Using the --force flag will ABSOLUTELY cause an outage.  When a device is removed from the fabric, all fabric related configs are also removed, therefore you will see traffic loss.  This is an optional flag and is not required.  Once you have registered the devices in Inventory, and then added them to the fabric, you should be able to do a normal "efa fabric configure --name [fabric_name]" to push the fabric configs to the new leaf devices. 

In summary I would recommend:

1.) "efa inventory device register --ip [device_ip(s)] --username [user] --password [pass]"

2.) "efa fabric device add|add-bulk ..."

3.) "efa fabric configure --name [fabric_name]"

Best of luck,