1 == How To Install Ganeti Clusters and Instances ==
5 Suppose that there are two identical hosts: foo.debian.org and bar.debian.org.
7 They are running squeeze and have been integrated into Debian infrastructure.
9 They will serve as nodes in a ganeti cluster named foobar.debian.org.
11 They have a RAID1 array exposing three partitions: c0d0p1 for /, c0d0p2 for
12 swap and c0d0p3 for lvm volume groups to be used by ganeti via drbd.
14 They have two network interfaces: eth0 (public) and eth1 (private).
16 The public network is A.B.C.0/24 with gateway A.B.C.254.
18 The private network is E.F.G.0/24 with no gateway.
20 Suppose that the first instance to be hosted on foobar.debian.org is
23 The following DNS records exist:
26 foobar.debian.org. IN A A.B.C.1
27 foo.debian.org. IN A A.B.C.2
28 bar.debian.org. IN A A.B.C.3
29 qux.debian.org. IN A A.B.C.4
30 foo.debprivate-hoster.debian.org. IN A E.F.G.2
31 bar.debprivate-hoster.debian.org. IN A E.F.G.3
34 === install required packages ===
36 On each node, install the required packages:
39 apt-get install fai-client ssed extlinux
40 apt-get install -t squeeze-backports drbd8-utils ganeti2 ganeti-instance-debootstrap ganeti-htools
43 === configure kernel modules ===
45 On each node, ensure that the required kernel modules are loaded at boot:
48 ainsl /etc/modules 'drbd minor_count=255 usermode_helper=/bin/true'
49 ainsl /etc/modules 'hmac'
50 ainsl /etc/modules 'tun'
53 === configure networking ===
55 On each node, ensure that br0 (not eth0) and eth1 are configured.
57 The bridge interface, br0, is used by the guest virtual machines to reach the
60 If the guest virtual machines need to access the private network, then br1
61 should be configure rather than eth1.
63 To prevent the link address changing due to startup/shutdown of virtual
64 machines, explicitly set the value.
67 # /etc/networking/interfaces for foo.debian.org
77 up ip link set addr $(cat /sys/class/net/$IFACE/address) dev $IFACE
80 iface eth1 inet static
87 On each node, configure lvm to ignore drbd devices and to prefer
88 {{{/dev/cciss}}} devices names over {{{/dev/block}}} device names
89 ([[http://code.google.com/p/ganeti/issues/detail?id=93|why?]]):
93 -e 's#^\(\s*filter\s\).*#\1= [ "a|.*|", "r|/dev/drbd[0-9]+|" ]#'
94 -e 's#^\(\s*preferred_names\s\).*#\1= [ "^/dev/dm-*/", "^/dev/cciss/" ]#' \
99 === create lvm volume groups ===
101 On each node, create a volume group:
104 vgcreate vg_ganeti /dev/cciss/c0d0p3
107 === create kvmU symbolic links ===
109 On each node, create vmlinuz and initrd symlinks as expected by the kvm
113 ln -s -T /boot/vmlinuz-2.6.32-5-amd64 /boot/vmlinuz-2.6-kvmU
114 ln -s -T /boot/initrd.img-2.6.32-5-amd64 /boot/initrd.img-2.6-kvmU
117 === exchange ssh keys ===
119 ipsum loren bacon puppet
121 === configure iptables (via ferm) ===
123 ipsum loren bacon puppet
125 === instantiate the cluster ===
127 On the master node (foo) only:
131 --master-netdev br0 \
132 --vg-name vg_ganeti \
133 --secondary-ip E.F.G.2 \
134 --enabled-hypervisors kvm \
135 --nic-parameters link=br0 \
136 --mac-prefix 00:16:37 \
139 --hypervisor-parameters kvm:initrd_path=/boot/initrd.img-2.6-kvmU,kernel_path=/boot/vmlinuz-2.6-kvmU \
145 * the master network device is set to br0, matching the public network bridge interface created above
146 * the volume group is set to vg_ganeti, matching the volume group created above
147 * the secondary IP address is set to the value of the master node's interface on the private network
148 * the nic parameters for instances is set to use br0 as default bridge
149 * the MAC prefix is registered in the dsa-kvm git repo
151 === add slave nodes ===
153 For each slave node (only bar for this example), on the master node (foo):
157 --secondary-ip E.F.G.3 \
165 * the secondary IP address is set to the value of the slave node's interface on the private network
167 === verify cluster ===
169 On the master node (foo):
175 If everything has been configured correctly, no errors should be reported.
177 === create the 'dsa' variant ===
179 ipsum loren bacon deboostrap+dsa
183 == How To Install Ganeti Instances ==
185 Suppose that qux.debian.org will be an instance (a virtual machine) hosted on
186 the foobar.debian.org ganeti cluster.
188 Before adding the instance, an LDAP entry must be created so that an A record
189 for the instance (A.B.C.4) exists.
191 === create the instance ===
193 On the master node (foo):
198 --disk-template drbd \
200 --os-type debootstrap+dsa \
201 --hypervisor-parameters kvm:initrd_path=,kernel_path= \
208 * the primary and secondary nodes have been explicitly set
209 * the operating system type is 'debootstrap+dsa'
210 * the network interfarce 0 (eth1 on the system) is set to the instance's interface on the public network
216 If the instances require access to the private network, then there are two modifications necessary.
218 === re-configure networking ===
220 Ensure that br1 is configured (rather than eth1).
223 # /etc/networking/interfaces for foo.debian.org
226 iface br0 inet static
231 netmask 255.255.255.0
233 up ip link set addr $(cat /sys/class/net/$IFACE/address) dev $IFACE
236 iface br1 inet static
241 netmask 255.255.255.0
242 up ip link set addr $(cat /sys/class/net/$IFACE/address) dev $IFACE
245 === create or update the instance ===
247 When creating the instance, indicate both netwokrs:
252 --disk-template drbd \
254 --os-type debootstrap+dsa \
255 --hypervisor-parameters kvm:initrd_path=,kernel_path= \
256 --net 0:ip=A.B.C.4,1:ip=E.F.G.4 \
260 Please note that the dsa bootscript will only configure eth1 (nic0). If
261 specifying a second internface, the guest operating system must be updated
264 When updating an existing instance, add the interface:
267 gnt-instance shutdown qux.debian.org
268 gnt-instance modify \
269 --net add:ip=E.F.G.4 \
271 gnt-instance startup qux.debian.org
274 Please note that the hook scripts are run only at instance instantiation. When
275 adding interfaces to an instance, the guest opearting system must be updated