Creating Linux Instances¶

• Creating Linux Instances
  • Create Debian instance.
    • SSH
  • Instance import
  • Create another GNU/Linux instances
    • Create Ubuntu instance

Create Debian 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. You should also specify metavg=... for disk on such group.

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

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

Create another GNU/Linux instances¶

Create Ubuntu instance¶

There is os variant ubootstrap+default for Ubuntu.
To create ubuntu instance execute command like this:

gnt-instance add -t drbd -o ubootstrap+default -s 4g -B memory=512m -n gnt1:gnt2 ubuntu