Add information about creating geth instances to README.md

README.md

@@ -152,6 +152,33 @@ Do this if you want to use the remote server for building and deploying.
 
     Where the `$user` shell variable contains the name of your shell account on the remote machine.
 
+### Setting up Ethereum client on a separate machine
+This step installs and configures Geth on a separate machine in Google Compute Engine.
+This is optional since Geth be deployed automatically as a part of a Concent cluster but when you have multiple clusters, having one shared instance of the client allows you to use less resources.
+Concent does not use Geth very heavily so one instance of the blockchain client can handle many Concent instances.
+It also makes deployment faster and more reliable since it's not necessary to wait for Geth synchronization every time it's updated or redeployed.
+
+This machine comes in two flavors: `ethnode-testnet` and `ethnode-mainnet`.
+If you're running both test clusters and a production cluster, you need both.
+
+The playbooks need to be run from `concent-builder` or another machine that is authorized to run `gcloud` commands on the Google Cloud project.
+To create and configure the machine run the playbooks listed below.
+The first one creates the cloud instance, reserves IP and provisions a disk.
+This operation requires permissions to the Google Cloud project
+The `$ethnode` variable specifies the flavor of the machine to be created: `ethnode-testnet` or `ethnode-mainnet`.
+The second one connects to the machine, installs everything on it and starts Geth.
+``` bash
+cd concent-deployment/cloud/
+ansible-playbook create-vm-instances-for-geth.yml                   \
+    --extra-vars "ethnode=$ethnode"                                 \
+    --inventory  ../../concent-deployment-values/ansible_inventory  \
+    --user      $user
+
+ ansible-playbook configure.yml                                     \
+    --extra-vars "ethnode=$ethnode"                                 \
+    --inventory  ../../concent-deployment-values/ansible_inventory  \
+    --user      $user
+```
 
 ### Uploading secrets and access to deploy on specific gcloud environment
 This is a separate step that is needed on the new server and in the case of changes in secrets