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.

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