Virtualized gLite services

There are several projects that are using or aiming to use VMs for running gLite services. This is a list of such projects.

• Xen-strap (http://www.gridpp.ac.uk/wiki/Xen-strap, http://www.gridpp.ac.uk/wiki/Glite-UI-on-SL4)
• gLite testing (Andreas Unterkircher).
• INFN-GRID (Leonello Servoli) are developing high-availability gLite services with failover VMs. VM state is kept in network block devices, and if one service, VM or hardware fails, then the VM is continued on a different physical machine. They use cfengine for configuration automation and nagos for monitoring.

Running gLite services in Xen VMs is straight forward. There are some points worth mentioning:

• By default, the hwclock in a Xen domain is read-only, and can cause problems with ntp.
• Software updates may cause /lib/tls to be overwritten.
• At least one IP address should be allocated per domain, or IP setup can be quirky.
  

http://cern.ch/osfarm

http://project-xen.web.cern.ch/project-xen/xen/img/img.xml

-- Main.hbjerke - 19 Jan 2007