Virtual Machines working group

Meetings

Kick-off - Monday July 6: agenda (dutch), minutes (dutch)

Presentations

Sky computing - Sander@nikhef.nl Klous, a summary of the CERN virtual machines workshop (see other information) and an introduction in the kick-off meeting of the BIG grid virtual machines working group.

Open Issues

• Network Address Translation - What is the load?<br\>
• Virtual Machine Isolation - Prohibit internal network connectivity with IPTables.<br\>
• Image repository - Storage Area Network or distributed over worker nodes.<br\>
• Policy document<br\>

Infrastructure

I am setting up a testbed to investigate technical issues related to virtual machine management.

Hardware and Operating Systems

• Two Dell 1950 machines, dual CPU, 4 cores per CPU
  • One machine has a CentOS-5 installation
  • One machine has a Debian-squeeze installation

Software

• CentOS-5 comes with Xen 3.0
• Debian-squeeze comes with Xen 3.3
  • Debian-squeeze Xen packages have a problem with tap:aio.

Fix:
ln -s /usr/lib/xen-3.2-1/bin/tapdisk /usr/sbin
echo xenblktap >> /etc/modules

• Opennebula has been installed (stand alone) on CentOS-5 following this guide
  • A few additional staps were needed:
    • Install rubygems and rubygem-sqlite3
    • Opennebula has to be added to the sudoers file for xm and xentop
    • Sudoers should not require a tty

wget ftp://fr.rpmfind.net/linux/EPEL/5/x86_64/rubygem-sqlite3-ruby-1.2.4-1.el5.x86_64.rpm
wget ftp://fr.rpmfind.net/linux/EPEL/5/x86_64/rubygems-1.3.1-1.el5.noarch.rpm
sudo rpm -Uvh rubygems-1.3.1-1.el5.noarch.rpm rubygem-sqlite3-ruby-1.2.4-1.el5.x86_64.rpm 

In /etc/sudoers (on all machines)
opennebula ALL = NOPASSWD: /usr/sbin/xm
opennebula ALL = NOPASSWD: /usr/sbin/xentop
#Defaults    requiretty

• Installed iSCSI target and client software for shared image repository
  • Howtos: Debian client/server, CentOS client, CentOS server
  • Maybe test later with encrypted iSCSI
  • Two new machines ordered with the required iSCSI offload
• Image repository consists of LVM volume groups
  • Performance of LVM is better than file based images
  • Each logical volume contains an image
  • This allows easy creation/deletion of new images
  • VMs can run from cloned (Copy-On-Write) images
• Implemented iSCSI image management for opennebula following the storage guide
  • Changed oned configuration
  • Added tm_iscsi configuration
  • Implemented transfer manager commands

In /opt/opennebula/etc/oned.conf:
TM_MAD = [
   name       = "tm_iscsi",
   executable = "one_tm",
   arguments  = "tm_iscsi/tm_iscsi.conf",
   default    = "tm_iscsi/tm_iscsi.conf" ]

/opt/opennebula/etc/tm_iscsi/tm_iscsi.conf
/opt/opennebula/etc/tm_iscsi/tm_iscsirc

/opt/opennebula/lib/tm_commands/iscsi/tm_clone.sh
/opt/opennebula/lib/tm_commands/iscsi/tm_delete.sh
/opt/opennebula/lib/tm_commands/iscsi/tm_ln.sh
/opt/opennebula/lib/tm_commands/iscsi/tm_mkimage.sh
/opt/opennebula/lib/tm_commands/iscsi/tm_mkswap.sh
/opt/opennebula/lib/tm_commands/iscsi/tm_mv.sh

Other information

• CERN June 2009 workshop on virtual machines