Booting the network
This document covers restarting the network in the case where all servers are powered off.
Overall boot order
Generally switches and the modem will come on automatically, if there is doubt check at minimum the switches in the rack and the cable modem are powered up.
DNS and LDAP are an integral part of the server operation, as such until they are running all servers will encounter multiple timeouts. This can lead to the first server having a boot time in excess of 15 minutes, during most of that time it will not give any indication of progress. All servers may be booted in parallel, but will encounter significant delays in the boot process until DNS and LDAP become available. Therefore it is best to prioritize the servers as follows:
The first server to is the physical server which hosts the primary DNS and LDAP. This will be a Xen server with a virtual server on it. As of the time of writing this was teak.shop.lan; refer to the hosts list for the current VM and which machine it is on.
The second server which should be booted is the router, this will allow internet access and may help speed up certain parts of the other boots.
Once those two servers are booting/booted any and all remaining servers may be booted in whatever order is convenient, refer to documentation as to which servers are currently in production as there are usually more servers racked than need to be powered on.
Booting an individual server
There are two types of servers when it comes to booting, regular servers and virtual machine hosts or xen servers. Both servers may be booted normally by selecting the first entry in GRUB, and the first entry in any subsequent GRUB menus if there is more than one. By default all servers should automatically boot their default entry unless interrupted by keyboard input.
Due to the software on the Xen servers a regular boot directly to a linux kernel will not generally work. If a recovery mode boot is required the first entry on the first menu should be selected which will be something like 'Xen 4.1-i386' and then the recovery option may be selected on the second menu. Regular servers may directly select a recovery boot item like usual.
Note on rolling maintenance order
Due to reliance on LDAP/DNS for booting the boot time can be greatly reduced if a DNS and LDAP service are up during all boots. In the case where multiple servers are being rebooted it is best to reboot one of the servers hosting a DNS/LDAP VM (either master or slave) and let that machine come back up before rebooting the other server with DNS/LDAP.