The advanced config option SunRPC.MaxConnPerIP does not take effect

Products

• VMware vSphere ESXi

Issue/Introduction

The value set for the advanced config option SunRPC.MaxConnPerIP is not considered while mounting new NFSv3 datastores. Each new NFSv3 datastore has distinct RPC clients.

Environment

VMware vSphere ESXi 8.0.1
VMware vSphere ESXi 8.0.x

Resolution

The nConnect feature in NFSv3 introduced multiple RPC connections for a single NFSv3 datastore. With this feature, each RPC client needs to hold a reference to the datastore that it belongs to, thus limiting the ability to share RPC connections across different NFSv3 datastores.

Note:

nConnect feature is available as a tech preview(exprimental) feature in 8.0u1. However with this change SunRPC.MaxConnPerIP will not be effective.

1. The list of other advanced NFS options can be found in Definition of the advanced NFS options.

2. The command to list the number of RPC clients currently in use by mounted NFSv3 datastores

[root@esx-host] vsish -e get /vmkModules/nfsclient/info
NFS Connections Info {
mountedVolumes:64
totalConnections:256
}

3. The command to list the RPC client IDs for a given NFSv3 datastore,

[root@esx-host:~] vsish -e ls /vmkModules/nfsclient/mnt/nfs-datastore1/rpcClients
18

4. The RPC IDs can be mapped further using the command,

[root@esx-host:~] vsish -e ls /vmkModules/sunrpc/clients/
18/