Ensure Cloud Compatibility of On Premise VMs

By CIOReview | Wednesday, August 10, 2016

Virtualization essentially wraps up applications and processes and is thus easier to move workloads to the cloud ecosystem. Several cloud providers have readily available options and offerings to port on premise Virtual Machines (VMs) on to the cloud.. With that being said, moving VMs to the cloud is neither as easy as uprooting the sapling to replant it; nor should IT administrators expect it to ‘grow’ (scale and adapt) on its own in tune with the allocated resources in the cloud platform. While on premise VMs on bare metal is like a mere bonsai treatment to the existing assets, a virtualized cloud ecosystem is analogues to a massive reforestation strategy. Just as one would assess the ‘environment’ before cultivating a plantation, certain prerequisites and configuration aspects have to be taken in to account while considering migrating VMs to the cloud.

Migration processes vary depending on the hypervisors used and cloud service providers be it VMWare, Amazon’s EC2 or Microsoft Azure to name a few. The cloud has its own set of challenges like concerns in security and speed which should not be overshadowed by its promises of virtualization, standardization and automation. Once firms have determined to evoke transition to the cloud after weighing its pros and cons by considering factors like cost, application performance, compatibility and portability; it is about time they considered making their VMs cloud ready.

On bare metal, VMs often enable pass through disks, a feature that allows them to make use of a physical disk rather than relying exclusively on virtual disks. When migration to cloud becomes imperative, it is recommended that firms entirely refrain from using pass through disks replacing them with virtual drives unless it is unavoidable in the business process.

The cloud platform does not necessarily support all the configurations of on-premise VM even though it supports its migration. It is therefore important to draw clarification from the service provider regarding supported configurations.  For instance, it has been observed that although some prominent cloud service providers support migrating Hyper-V VMs only if they are configured to use the older virtual hard disk format (VHD-based virtual hard disks). Methods of configuring cloud infrastructure banks upon Application Programming Interfaces (APIs) and/or VMs which demands clear understanding of the organization’s functions and processes along with thorough scrutiny into the provisions of Service Level Agreements (SLA).

Benchmarking VMs prior to cloud migration would provide better insights for on-cloud resource allocations. More often than not, VMs might not be able to retain their exact configuration through the migration process; one such factor is the VM size, a predefined hardware configuration that would determine the number of cores, memory and type of storage that VMs be allocated. Over provisioning or going by the word of the vendor is often not a good practice as the former would lead to wastage of resources while the latter is often quoted at the interest of the vendor. While allocating additional vCPU may seem free, T&Cs of software license are bound by processor counts that could lead to unforeseen license fees. Besides, adding memory to a VM could lower the overall number of VMs that a server can support which would in turn limit workload consolidation initiatives and balancing schemes causing businesses to buy more servers or storage than required and end up shelling out money for maintenance as well.

As migration to cloud proceeds, keeping track of resource usage through a chargeback or show-back model ensures its fair consumption. Additionally enterprises also need to consider and evaluate several security features that come bundled with cloud offerings such as VM firewalling and intrusion detection, agent-free antivirus scanning and disaster recovery to name a few. It is always a good practice to start small and grow as needed, after all the underlying reason for cloud migration is scalability.

When cloud services promise scalability, it is natural to expect a degree of speedy recovery from backups aimed at reducing downtime. Traditional backup options such as Full Backups, Incremental, Differential and Synthetic Backup can very well be incorporated on to the cloud. However, advancement in encryption, disaster recovery preparedness and virtualization has rendered notable innovations such as Snapshots, Flat Backup and Instant VM Recovery. Depending upon the sensitivity and crucial nature of data, organizations ranging from enterprises to government entities now have a number of options on the table to enforce strategies to secure as well as backup data.