Adaptive Infrastructure with a Twist
Scalent V/OE 2.0 divides servers from hardware, virtual platforms
Meet Your Personas
I took a look at the forthcoming release of V/OE 2.0, and it’s quite complex. It involves a controller built on a Red Hat Linux base that essentially has its way with all associated network switches and server hardware. Switch interactions are handled via SNMP; the server side is driven by IPMI (Intelligent Platform Management Interface)-compliant lights-out management features or a virtualization platform such as Microsoft Virtual Server, VMware, or XenSource.
Because of these requirements, V/OE has a relatively short list of supported hardware, including that of major vendors such as Cisco, Dell, HP, and Sun. I worked with a selection of servers, including three HP ProLiant DL360s, a Sun v20x server, and a Dell PowerEdge 2800 that I added later in the testing. One of the DL360s was running VMware ESX Server 2.5.2 with a single local disk, and the others were diskless. Installation is also quite complex, so Scalent sends an engineer to do the initial build of the infrastructure, including assistance in building the initial server personas.
A server persona is a server built for a certain task, replete with applications installed and con!gured. For instance, an Apache Web server could be built on any physical server, con!gured, have an application installed, and then be condensed into a persona. " e same goes for Windows 2003 Servers, as well as for Sun Solaris 10 SPARC and x86 systems. All of this is hardware-independent. A persona could be created on an HP ProLiant DL360, but then deployed on a DL380 or even as a VMware ESX 2.5 guest server.
"ere are some di#erences in the way personas are built, depending on operating system. Linux personas are generally built and run as netboot systems, with their system residing on an NFS server central to the solution. Windows servers cannot leverage the netboot/NFS simplicity, and they are subsequently booted from an iSCSI or FC SAN that contains a disk image of the server. "eiSCSI booting is handled via emBoot, with the initial boot stage run via PXE, the same as all other servers.
The Scalent Agent, the second piece of the puzzle, is the key to the true hardware/OS abstraction. Each persona runs an instance of Agent, which interacts with the controller to determine network and SAN connection parameters, IP addresses, and other ancillary data for the proper placement and configuration of the server persona on its hardware. Booting the server personas from the network also eliminates the need for a local disk on most servers.