Add gitaly source installation instructions

1 files changed, 11 insertions, 3 deletions

diff --git a/doc/update/8.17-to-9.0.md b/doc/update/8.17-to-9.0.md
index b7ba970031c..140d3684c56 100644
--- a/doc/update/8.17-to-9.0.md
+++ b/doc/update/8.17-to-9.0.md
@@ -145,7 +145,15 @@ sudo -u git -H git fetch --all --tags
 sudo -u git -H git checkout v5.0.0
 ```
 
-### 9. Update configuration files
+### 9. Optional: install Gitaly
+
+Gitaly is still an optional component of GitLab. If you want to save time
+during your 9.0 upgrade **you can skip this step**.
+
+If you do want to set up Gitaly in GitLab 9.0 then follow [Gitaly section of the installation
+guide](https://gitlab.com/gitlab-org/gitlab-ce/blob/9-0-stable/doc/install/installation.md#install-gitaly).
+
+### 10. Update configuration files
 
 #### New configuration options for `gitlab.yml`
 
@@ -282,14 +290,14 @@ For Ubuntu 16.04.1 LTS:
 sudo systemctl daemon-reload
 ```
 
-### 10. Start application
+### 11. Start application
 
 ```bash
 sudo service gitlab start
 sudo service nginx restart
 ```
 
-### 11. Check application status
+### 12. Check application status
 
 Check if GitLab and its environment are configured correctly: