We have high hopes for FastScale’s combination of products as it cuts away needless junk from virtual instances, making operating system and application instances lean and unencumbered by unused code. FastScale’s product can shoehorn many more atomic scaled-down virtual machines onto a VMware host licence than might normally be otherwise possible.
The FastScale Composer Suite includes FastScale Composer, which builds a repository of necessary operating system and applications components, and Virtual Manager, which then provisions these components as atomic processes as VMware instances running on RedHat Enterprise Linux (RHEL) 4/SELinux and CentOS 4 servers.
The bundle costs $50,000 in its entirety, ($30,000 without Virtual Manager) for 25 provisionable servers. FastScale’s strength comes from analysing active Linux applications and cutting away everything but kernel code, the application itself and any resources required to support them. The product creates an instance by ‘watching’ an existing application in action, then ‘blueprints’ what it’s found into a virtual machine object, figuring out its system requirements and software dependencies. The subsequent VMs produced using the repository include only what’s needed, rather than a long list of extraneous components (like unneeded DNS, printing daemons and NFS software) as well as superfluous code like obsolete driver files and /usr/bin applications that may never be called into actual action.
These software instances then become what FastScale calls a ‘Dynamic Application Bundle’ (DAB). New servers are created across what FastScale calls a Virtual Rack, which is simply a virtual representation of FastScale-provisioned VMware servers that are all provisioned through downloads in a PxE boot network. DABs are then provisioned to the nodes within the VMWare servers as VMWare Virtual Machine Disk Images. The image is loaded, and the server and applications go on their merry way. Patches for both the virtual machine operating systems as well as the applications running on them are placed into the object repository and then deployed across to all DABs as needed.
In our test gauging the reduction in overall foot print, we ran an Apache 2.0.52 Web server on our CentOS4 operating system on a Dell PowerEdge 1950 server. The initial sparse footprint totalled a minimum of 323MB of disk files, and a profile of 193MB of operating system, minimum system component daemons and the Apache Web server with hosted pages.
Just watching FastScale can be a heartening exercise in high-speed virtual machine dieting. After running FastScale on this instance, the same mix was startlingly small: 41MB of disk files, and 21MB memory use for all application objects in memory. Your reduction mileage will vary, but we found at least a 3-to-1 reduction in footprint for memory use, coupled with a discernible decrease in CPU utilisation.