add information about ordering linux system

_toc.yml

@@ -9,6 +9,7 @@ defaults:
 chapters:
   - file: user-guide/index
     sections:
+      - file: user-guide/order_linux_system
       - file: user-guide/login_servers
       - file: user-guide/linux_terminalserver
       - file: user-guide/windows_drives_in_home

user-guide/order_linux_system.md

@@ -0,0 +1,22 @@
+# Order / Replacement Linux System / Console
+To order a new/replacement Linux system / console proceed to the ServiceNow Service Catalog > IT > IT Workspace.
+After choosing the hardware you might want to add additional information into the __Additional order information__ field so that your order can be processed faster:
+
+- Operating system Linux RHEL8, RHEL9 ...
+- Purpose of the hardware
+  - Is it a workstation or beamline/endstation console?
+  - Is additional hardware needed - e.g. additional graphics card to connect multiple monitors
+- Is it a replacement for an existing system? If yes, which system? should the name be kept?
+
+- Hostname
+- Hiera environment (if you don't know what this is - please ignore)
+- Puppet group/subgroup (if you don't know what this is - please ignore)
+- Network (role in PacketFence)
+
+# Reinstallation
+For a reinstallation of a system please open a general ServiceNow ticket. Important information that should be included in the ticket are:
+
+- Information on whether this system was a Windows system before?
+- MAC address
+- Hiera environment (if you don't know what this is - please ignore)
+- Puppet group/subgroup (if you don't know what this is - please ignore)