DOC-4690 added details of --installation-dir option

Author: andy-stark-redis

content/integrate/redis-data-integration/installation/install-vm.md

@@ -177,6 +177,20 @@ Follow the steps below for each of your VMs:
     ```bash
     sudo ./install.sh
     ```
+
+    {{< note >}}RDI uses [K3s](https://k3s.io/) as part of its implementation.
+    By default, the installer installs K3s in the `/var/lib` directory,
+    but this might be a problem if you have limited space in `/var`
+    or your company policy forbids you to install there. You can
+    select a different directory for the K3s installation using the
+    `--installation-dir` option with `install.sh` (or
+    [`redis-di install`]({{< relref "/integrate/redis-data-integration/reference/cli/redis-di-install" >}})):
+
+    ```bash
+    sudo ./install.sh --installation-dir <custom-directory-path>
+    ```
+    {{< /note >}}
+
 RDI uses a database on your Redis Enterprise cluster to store its state
 information. *This requires Redis Enterprise v6.4 or greater*.
 

content/integrate/redis-data-integration/reference/cli/redis-di-install.md

@@ -40,6 +40,12 @@ Usage: redis-di install [OPTIONS]
 
   Run installer in online mode
 
+* `installation-dir`:
+  * Type: STRING
+  * Default: `/var/lib`
+  * Usage: `--installation-dir`
+
+  Custom installation directory
 
 * `help`: 
   * Type: BOOL 
@@ -62,5 +68,7 @@ Options:
                                   [default: WARN]
   -f, --file FILE                 Path to a TOML configuration file for silent
                                   installation
+  --installation-dir              Custom installation directory
+
   --help                          Show this message and exit.
 ```