Product helps stuff more VMs onto your physical servers
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 license than might normally be otherwise possible.
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 license 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 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 statistically analyzing 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 totaled 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 utilization.
A smaller instance also means that the ability for the application to use virtual RAM disks is possible, therefore enhancing overall speed as the amount of server memory used to support any application is reduced.
The fat that’s cut away after an analysis by FastScale is stored in an off-host repository service should something unforeseen be needed by the virtual machine or its applications. Applications that are used to having resident resources didn’t balk when we disguised their use. The production images resulting from FastScale’s slimming exercise in our testing executed without needing to go to the repository to get additional applications or support files.
We did use a PHP program to trigger files that might be needed to see how FastScale would react. The product supplied us with the files we needed, fetching from the CentOS repository we’d built, as advertised; a process that took under a second from need to fulfillment. Furthermore, when we checked to see if the application had found what it was looking for — and FastScale updated not only that particular instance, but also the repository information concerning the need for the code we’d called by surprise.
Moving onto management FastScale Virtual Manager is the provisioning component for FastScale-formed virtual operating system/application instances. Using the Virtual Rack, an instance can be moved very simply from the repository into a production VMware environment. We encountered no errors in the process, but we’d like to see a build authentication/vetting method that has the ability to “lock down” the repository to ensure that builds aren’t tampered with.
Unwitting access to the repository could render stored images and extra files into an unknown/insecure state. It may also be possible to wire-rip (capture the images) of the files during PxE provisioning, which is less unlikely but not impossible. However, we’ve also got to point to the added security benefit of a sparse operating system/application instance. A FastScale image means the security footprint becomes much smaller, with no unnecessary daemons or vulnerable applications running, waiting to be attacked.
Overall, FastScale doesn’t perform strong image instance authentication, nor does it perform details associated with user administration, leaving these to VMware and third party VMware-compatible applications. If you’re a Linux CentOS/RHEL administrator using VMware — an admittedly confining profile — FastScale has a cool-factor in the red zone. FastScale’s methodology will be put to the test in the future when Windows Server images are subjected to its diet regime something in 2008.
(Compare physical and virtual server management tools in our revamped Server Management Buyer’s Guide.)
Henderson is principal researcher and Dvorak is a researcher for ExtremeLabs in Indianapolis. They can be reached at thenderson@extremelabs.com.
Henderson is also a member of the Network World Lab Alliance, a cooperative of the premier reviewers in the network industry each bringing to bear years of practical experience on every review. For more Lab Alliance information, including what it takes to become a member, go to www.networkworld.com/alliance.
