Disable git gc --auto

doc/install/installation.md

@@ -283,9 +283,13 @@ sudo usermod -aG redis git
     # Copy the example Rack attack config
     sudo -u git -H cp config/initializers/rack_attack.rb.example config/initializers/rack_attack.rb
-    # Configure Git global settings for git user, used when editing via web editor
+    # Configure Git global settings for git user
+    # 'autocrlf' is needed for the web editor
     sudo -u git -H git config --global core.autocrlf input
+    # Disable 'git gc --auto' because GitLab already runs 'git gc' when needed
+    sudo -u git -H git config --global gc.auto 0
+
     # Configure Redis connection settings
     sudo -u git -H cp config/resque.yml.example config/resque.yml

doc/update/8.6-to-8.7.md

@@ -86,6 +86,14 @@ sudo -u git -H bundle exec rake assets:clean assets:precompile cache:clear RAILS
 ### 7. Update configuration files
+#### Git configuration
+
+Disable `git gc --auto` because GitLab runs `git gc` for us already.
+
+```sh
+sudo -u git -H git config --global gc.auto 0
+```
+
 #### Nginx configuration
 Ensure you're still up-to-date with the latest NGINX configuration changes: