Basic cluster management¶

Check if all is ok¶

gnt-cluster verify

Show detailed information¶

gnt-(cluster|node|instance) info

List objects¶

Nodes

gnt-node list

Configured instances

gnt-instance list

Create new instance¶

New instance on the NODE1 with failover on the NODE2, with one disk size 10Gb and 256M RAM.
INSTANCE_NAME must be resolvable via DNS.

gnt-instance add -t drbd -o debootstrap+default -s 10g -B memory=256m -n NODE1:NODE2 INSTANCE_NAME

Real example: create new instance

• on the node gnt2
• with failover on gnt1
• with three disks:
  • 10g on volume group xenvg
  • 600m on volume group xenvg (probably for swap)
• 5g on volume group xenvg
• DNS name vg-test1
• IP address will be configured automatically by resolving vg-test1' IP and matching it against /etc/ganeti/networks

gnt-instance add -t drbd -o debootstrap+default --disk 0:size=10g,vg=xenvg --disk 1:size=600m,vg=xenvg --disk 2:size=5g,vg=newvg -B memory=256m -n gnt2:gnt1 vg-test1

NOTE: the vg=.... option to specify different volume groups will be available since Ganeti 2.4.0 release.

Windows install¶

For windows install see WINDOWS-INSTALL

Instance import¶

For example, you have an image, tar, etc. of OS from other XEN machine.
To start it on sci-cd you must add instance with --no-install flag:

gnt-instance add -t drbd -B memory=5192m -n node1:node2 -o debootstrap+default --no-install --no-name-check --no-ip-check --net=0:link=dmz --disk 0:size=4G --disk 1:size=1024M --disk 2:size=100G --disk 3:size=50G terminal

--no-namecheck used when machine name doesn't resolv in any ip(ip may resolve my dns or /etc/hosts)
--no-ip-check used when no ip provided while creating instance

Instance manipulations¶

Various simple instance manipulations

gnt-instance (startup|shutdown|reboot|failover|remove|console) INSTANCE

OS command execution¶

Run OS command on all nodes

gnt-cluster command .....

SSH¶

All new instances, including 'sci' are going with empty root password and no ssh server installed.
You should first log in to the instance using gnt-instance console INSTANCE command, then set
root's password using passwd command and install ssh server using

apt-get install openssh-server

If you are using windows, you must download any ssh client, e.g. putty:
http://the.earth.li/~sgtatham/putty/latest/x86/putty.exe