+++ /dev/null
-Configuring mclu
-----------------
-
-Introduction
-------------
-
-mclu is based around the idea that you have a small collection of
-fairly similar "nodes". Ideally they would be identical nodes, if you
-want live migration to work seamlessly, but they don't have to be.
-
-Here is a picture of the cluster that I run mclu on:
-http://rwmj.wordpress.com/2014/04/28/caseless-virtualization-cluster-part-5/#content
-
-Nodes, control node, NFS server
--------------------------------
-
-There is also one "control" node, which could be your laptop or could
-be one of the cluster nodes. This is where you run the 'mclu'
-command, and also where the single configuration file is located
-(mclu.conf, usually located in /etc/mclu).
-
-Each node must be accessible from the control node over ssh. Each
-node must be running the libvirt daemon (libvirtd).
-
-mclu uses a mix of ssh commands and remote libvirt to manage the
-nodes. You should configure ssh so it can access the nodes without
-needing passwords (eg. using ssh-agent). If you use the default
-libvirt URI (see config file) then you also need to set up
-passwordless root ssh access to the nodes; there are other ways to
-configure this, eg. opening the libvirtd port on each node, but they
-are probably not as secure.
-
-Each node, including the control node, must have access to shared
-storage where the guest disk images are stored. The easiest way to do
-this is to export /var/lib/libvirt/images from one machine and
-NFS-mount it on all the nodes (and also to have a nice fast network).
-Cluster filesystems are another possibility. mclu does NOT support
-non-shared storage nor storage migration.
-
-Wake-on-LAN
------------
-
-The nodes can be up or down. mclu deals transparently with nodes
-being switched off. If you configure wake-on-LAN (usually a BIOS
-setting) then mclu will be able to wake up nodes.
-
-Running guests
---------------
-
-The guest libvirt XML files are also stored on the control node
-(usually /etc/mclu/xmls). Guests are created as transient, which
-means the libvirt daemon running on each node does not have a
-persistent configuration of any guest.
-
-Guests run on a single node at a time. You can list/start/stop/
-migrate them using mclu. The requirement for a guest to be running on
-a single node may be enforced if you run libvirt sanlock or virtlockd.
-This requires further configuration, see:
-http://libvirt.org/locking.html
-https://rwmj.wordpress.com/2014/05/08/setting-up-virtlockd-on-nfs/#content
-
-If sanlock/virtlockd is not running then mclu will try its best not to
-have the guest running in two places at once (if it happens, this will
-cause permanent disk corruption in the guest).
-
-Migration
----------
-
-For guest live migration to work transparently, you will probably want
-to configure libvirt bridged networking and open firewall ports
-49152-49215 on every node.
-
-Bridged networking means that each guest appears as a local machine on
-your network, and if it migrates then network connections will not be
-interrupted. See:
-http://wiki.libvirt.org/page/Networking#Bridged_networking_.28aka_.22shared_physical_device.22.29
-
-The firewall ports have to be opened because libvirt cannot (yet?) do
-fully managed migration over two SSH connections (even though the
-documentation says it can). Hopefully they will fix this soon.
-
-Editing guest configuration or disk images
-------------------------------------------
-
-The guest configuration (libvirt XML) is stored in the xmls directory
-(usually /etc/mclu/xmls). You can edit this file directly if you want.
-Changes will not take effect until the guest is restarted.
-
-The guest disk images are located in the images directory (usually
-/var/lib/libvirt/images). You can use libguestfs against these in
-read-only mode (or read-write mode PROVIDED the guest is not running).
-
-You can also create or import guests by dropping an XML file and an
-image into those directories. (But it might be easier to use the
-'mclu build' and 'mclu import' subcommands).
-
-SELinux
--------
-
-I have SELinux enabled on all nodes of my cluster. However it wasn't
-easy to get this far. In particular you need to enable one or
-probably both of these booleans:
-
- setsebool -P virt_use_nfs on
- setsebool -P use_nfs_home_dirs on
-
-Other tips
-----------
-
-Install ntp on all the nodes so that the date is kept in synch.
-
-Install lm_sensors on all nodes so you can monitor temperature, fan
-speed and so on.
git.annexia.org / mclu.git / blobdiff