Trying to add persistence profile in existing virtual server

I do not know PowerShell, but from the error message,

The requested virtual server 
(/Common/iControl.CommonVirtualServerDefinition) was not found

, I would say that the virtual does not exist. Check if exists.

If that's not the case, I suspect the data format of the persistence profile(s). It must be given in array (

[]

). For example, to perform the task equivalent to the following tmsh command (adding

cookie

persistence profile to the virtual

vs

😞

tmsh modify ltm virtual vs persist replace-all-with { cookie }

You need to PATCH the

/mgmt/tm/ltm/virtual/vs

endpoint with the data

{"persist":[ {"name":"cookie"} ]}

.

A curl call looks like this:

curl -sku : https:///mgmt/tm/ltm/virtual/vs \
  -X PATCH -H "Content-type: application/json" \
  -d '{"persist":[ {"name":"cookie"} ]}'