Virtualization undoubtedly has brought a sea change in IT industry, but there are a few issues associated with it. Some of the top virtualization challenges are presented below:
- Licensing issues: Licensing is a serious issue faced during virtualization. For example, using server virtualization multiple software instances can be run concurrently on one machine, which may give rise to a case of non-compliance of terms and conditions. The implications of non-compliance can be significant for big enterprises as they spend a large part of their IT investment in software licensing (as much as 30%). Lately, application developers have been trying to adapt their licenses to include virtualization and many others have started collecting details of virtualization status by asking for example, virtual machines per server etc. before they grant the license.
- Virtual server sprawl: As in case of physical server sprawl, virtual servers sprawl leads to inefficiency and even potential security risk if it remains un-noticed by the administrators. Virtual machine server sprawls can be controlled by carefully defining roles and responsibilities and access privilege. Poorly planned virtual machines can easily erode all the advantages presented by virtualization.
- Network complexity – virtualization consolidates the servers but they still have significant network requirements, such as VLANs. Also, in a case of server failure multiple virtual machines are lost.
- Administration complexity and skill set requirement: While in a non-virtualized scenario, monitoring server performance and utilization was not a priority task; it becomes a critical one post virtualization implementation. Virtualization management tools provide information on virtualized elements and not exactly on the data center itself. On the other hand, tools handling data centers are not aware of virtualization components. This build to significant administrative complexities.
- Unexpected costs: Unexpected hardware and software requirements can occur which were not anticipated at the start. These generally occur to solve issues related to performance and management. One such example is storage capacity which may get exhausted very quickly leading to purchase of unbudgeted storage space.
- New compliance implementation – in almost all the cases, new compliance standards and methods of audit are implemented post virtualization.
- Security risk to virtual services layer (Hypervisor) – Hypervisor which sits between the hardware, all its devices and the OS is prone to malware attacks. In case of such attacks, all the virtual machines on a single server are then exposed causing a serious threat.