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--- archive_xen [2009/12/17 20:49] – I'm a massive fucking pedant. _seth
+++ archive_xen [2026/09/27 00:52] (current) – removed - external edit (Unknown date) 127.0.0.1
@@ Line 1: / Line 1: @@
-//Work in progress. -- Thom 17/12/09//
-====== Overview ======
-  *  We currently have two Xen hosts: [[wotan]] and [[oracle]].
-====== Creating new Xen instances ======
-==== Naming your host ====
-  *  Think of a name. We like Dr Who themed names! If you recycle a name you'll probably upset Thom -- why not ask Malcolm for advice?
-  *  At this point you should also create a wiki page explaining your VM's purpose and config. Use one of the other Xen machines' pages as a starting point.
-  *  Find a free IP and add forward and reverse mappings to the [[dns_service|DNS]].
-==== Find a Xen host ====
-  *  Our main constraints on Xen hosts are RAM and disk space.
-  *  Use ''vgs'' to show free disk space in the volume group
-  *  Check amount of RAM allocated to dom0 in ''xentop'' for a poor estimation of potentially free RAM.
-==== Create disk volumes ====
-  *  Create root volume: ''lvcreate -L 4GB -n <hostname>-root <volume-group>''
-    *  2GB is just about enough for a Debian install.
-    *  You can find out the volume group name with ''vgs''
-  *  Create swap volume: ''lvcreate -L 256MB -n <hostname>-swap <volume-group>''
-    *  Use your favourite rule of thumb for guessing a completely arbitrary quantity of swap space to allocate. If your machine starts thrashing you'll probably upset someone, so it's better off being small.
-==== Create Xen configuration file ====
-Combine the following config, as customized to your specifications, with the Debian xen installer config file
-http://ftp.debian.org/debian/dists/lenny/main/installer-i386/current/images/netboot/xen/xm-debian.cfg.
-Put the new config file in ''/etc/xen/<hostname>.conf''
-// Note. The IP bit is possibly redundant. Replace with blank string?//
-<code>
-memory = <amount of memory in MB>
-name = "<host-name>"
-vif = ['ip=<ip>']
-disk = [ 'phy:/dev/<volume-group>/<host-name>-root,xvda,w',
-         'phy:/dev/<volume-group>/<host-name>-swap,xvdb,w' ]
-#============================================================================
-# Debian Installer specific variables
-<<<INSERT REST OF DEBIAN XEN CONFIG FILE HERE>>>
-</code>
-==== Install Debian ====
-  *  There's probably a way to get the installer to load via an HTTP proxy, but I'm lazy so I just punch a temporary hole in the firewall:
-    *  ''ace:~# iptables -I FORWARD -s oracle -d ftp.uk.debian.org -j ACCEPT''
-  *  Start the installer
-    *  ''xm create -c ukairo.conf install=true install-mirror=ftp://ftp.uk.debian.org/debian''
-  *  Exciting installer notes!
-    *  DHCP got an address the first time round. It probably shouldn't have. Configure manually if you get the chance.
-      *  Gateway is ''.1'', DNS is ''.14''.
-    *  Configure the proxy as ''http://free.cache.ed.ac.uk:3218''
-    *  Partition manually. The installer gets confused otherwise
-    *  Be careful not to select "Desktop" in tasksel!
-      *  Also this doesn't pull in openssh-server, and makes things depend on X. This is bad. FIXME
-    *  Bootloader... WTF. FIXME.
-  *  Unbreak the firewall.
-    *  ''ace:~# iptables -D FORWARD -s oracle -d ftp.uk.debian.org -j ACCEPT''
-==== Booting your instance ====
-  *  Remove the Debian installer cruft from the config file.
-  *  Add kernel=, initrd=, and root= entries
-    *  There's probably a better way to do this, as this means we're missing modules... FIXME
-  *  ''xm create -c <newmachinename>.conf>''
-    *  Will boot instance and attach to console. Check you can log in.
-    *  Use ctrl+] to get back to the Xen host console.
-==== Finishing up ====
-  *  Congratulations, you now have a new Xen domU!
-====== Booting and Shutting Down ======
-Xen's init scripts are set up to perform an `xm save` (copy the RAM to disk) for each domU that's running when vislor and/or adric are shut down and to restore saved domUs on boot.  This should take care of the cases where tardis is shut down intentionally, but a bit more work will have to be done following an unexpected power loss.  (When do they happen anyway? ;-)
-To start all domUs on vislor do:
-  for foo in /etc/xen/*.conf; do xm create -c $foo; done
-  <WAIT FOR A LOGIN PROMPT>
-  ctrl+]
-  <WAIT FOR A LOGIN PROMPT>
-  ctrl+]
-  ....