Frequently Asked Questions - Virtual Servers

Virtual Servers

One of the big new technologies of 2008 was virtualisation. Although the concept had been around for many years, it wasn’t until the combination of power and energy savings, server consolidation, multi-core processing and remote server centres came together to create the perfect environment for mass adoption.

A virtual machine is a complete PC or server along with a virtual hard drive, memory and operating system running inside a type of emulator on a host machine. This allows you to run multiple virtual machines on one physical host server or PC that can be installed with applications and connected to your network as if they were real machines.

The advantages of running virtual machines include:

• Better utilization of server hardware for
• Fewer physical servers
• More energy-efficient server rooms
• Savings in new hardware budgets
• Faster deployment of new clean or standard build platforms
• Hardware independence, simply move from one physical server to another
• Simple whole server backup with quick restoration

Although the advantages of virtualization are many, there are some disadvantages to consider:

• Ensuring software is legally licensed can become complicated
• Virtual machine performance is often notably slower than a physical server
• Many types of hardware can’t be used in a virtual environment

We have implemented both TeleForm and LiquidOffice onto Microsoft Virtual Server 2005, Hyper-V and VMware ESXi for a variety of purposes. Most virtualisation solutions impact performance to some extent, so the usual application of a virtualised system is for Disaster Recovery or testing purposes. Careful consideration should be given to implementing a live system on a virtual environment.

Performance

Hard-drive performance is often much slower in a virtual environment. Although this may not preclude a virtualised server and reaping the benefits, it will be necessary to invest in faster hardware or multiple physical servers to achieve the same level of performance as a physical server.

Licensing

Microsoft limits the number of virtual servers you can run on a physical server with the physical servers’ license. Server 2008 Enterprise, for example allows four virtual servers whilst Server 2008 Standard only allows one. Supporting software such as SQL Server will also need to be licensed correctly along with the applications such as LiquidOffice and TeleForm.  Just because the software resides on a single physical server, don't assume software manufacturers allow a single license to be virtualised multiple times, even as only a backup.

Hardware compatibility

As previously explained, a virtual machine runs in an emulator which emulates the core hardware required to run an operating system such as a CPU, memory, graphics card, etc. This means that the virtual server only sees the emulated hardware and none of the real physical hardware. This provides the hardware independence allowing a virtual server to be moved from one physical server to another, of different hardware specification, and continue running without needing to even update any drivers.

The downside however, is that hardware such as fax cards, parallel ports and even physical network cards cannot be accessed by a virtual server. This would make it impossible to run a ZetaFax fax server on a virtual server with fax cards or to install TeleForm V8, or before, with a hardware key connected to a parallel port (Virtual Server 2005 and ESXi V3.5 do support parallel ports but Hyper-V does not).

It should be noted that TeleForm V10 requires machine locking during the activation process and this requires a physical network card. Whilst a Hyper-V virtual server could be used as a TeleForm SQL or file server, it could not be used for the activation or license service.  VMware's ESXi emulates network cards differently, so it can be used for the TeleForm activation process.

Whilst ePC has implemented and tested many combinations of hardware and software alongside LiquidOffice and TeleForm, we can't guarantee compatibility with all versions.  Please contact us with details of your specific requirements and we can advise further or arrange compatibility testing if required.