WIP getting started

1 files changed, 65 insertions, 7 deletions

diff --git a/doc/book/src/getting_started/cluster.md b/doc/book/src/getting_started/cluster.md
index a17bf14e..af6e8f10 100644
--- a/doc/book/src/getting_started/cluster.md
+++ b/doc/book/src/getting_started/cluster.md
@@ -1,14 +1,72 @@
 # Configure a cluster
 
+*We use a command named `garagectl` which is in fact an alias you must define as explained in the [Control the daemon](./daemon.md) section.*
+
+In this section, we will inform garage of the disk space available on each node of the cluster
+as well as the site (think datacenter) of each machine.
+
 ## Test cluster
 
+As this part is not relevant for a test cluster, you can use this one-liner to create a basic topology:
+
+```bash
+garagectl status | grep UNCONFIGURED | grep -Po '^[0-9a-f]+' | while read id; do 
+    garagectl node configure -d dc1 -n 10 $id
+done
+```
+
 ## Real-world cluster
 
-For our example, we will suppose we have the following infrastructure:
+For our example, we will suppose we have the following infrastructure (Tokens, Identifier and Datacenter are specific values to garage described in the following):
+
+| Location | Name    | Disk Space | `Tokens` | `Identifier` | `Datacenter` |
+|----------|---------|------------|----------|--------------|--------------|
+| Paris    | Mercury | 1 To       | `100`    | `8781c5`     | `par1`       |
+| Paris    | Venus   | 2 To       | `200`    | `2a638e`     | `par1`       |
+| London   | Earth   | 2 To       | `200`    | `68143d`     | `lon1`       |
+| Brussels | Mars    | 1.5 To     | `150`    | `212f75`     | `bru1`       |
+
+### Identifier
+
+After its first launch, garage generates a random and unique identifier for each nodes, such as:
+
+```
+8781c50c410a41b363167e9d49cc468b6b9e4449b6577b64f15a249a149bdcbc
+```
+
+Often a shorter form can be used, containing only the beginning of the identifier, like `8781c5`,
+which identifies the server "Mercury" located in "Paris" according to our previous table.
+
+The most simple way to match an identifier to a node is to run:
+
+```
+garagectl status
+```
+
+It will display the IP address associated with each node; from the IP address you will be able to recognize the node.
+
+### Tokens
+
+Garage reasons on an arbitrary metric about disk storage that is named "tokens".
+The number of tokens must be proportional to the disk space dedicated to the node.
+Additionaly, ideally the number of tokens must be in the order of magnitude of 100
+to provide a good trade-off between data load balancing and performances (*this sentence must be verified, it may be wrong*).
+
+Here we chose 1 token = 10 Go but you are free to select the value that best fit your needs.
+
+### Datacenter
+
+Datacenter are simply a user-chosen identifier that identify a group of server that are located in the same place.
+It is up to the system administrator deploying garage to identify what does "the same place" means.
+Behind the scene, garage will try to store the same data on different sites to provide high availability despite a data center failure.
+
+### Inject the topology
+
+Given the information above, we will configure our cluster as follow:
 
-| Location | Name    | IP Address | Disk Space |
-|----------|---------|------------|------------|
-| Paris    | Mercury | fc00:1::1  | 1 To       |
-| Paris    | Venus   | fc00:1::2  | 2 To       |
-| London   | Earth   | fc00:1::2  | 2 To       |
-| Brussels | Mars    | fc00:B::1  | 1.5 To     |
+```
+garagectl node configure --datacenter par1 -n 100 -t mercury 8781c5
+garagectl node configure --datacenter par1 -n 200 -t venus 2a638e
+garagectl node configure --datacenter lon1 -n 200 -t earth 68143d
+garagectl node configure --datacenter bru1 -n 150 -t mars 212f75
+```