Physical Servers vs. Virtual Machines: Key Differences and Similarities
By: NAKIVO Team
When starting a new business, you should make sure that your organization’s infrastructure can carry the workload and perform business operations without lags and interruptions. The infrastructure of your organization can be built on either a physical server, a virtual server, or the combination of both (a hybrid server). Therefore, it is essential to consider a number of factors when choosing between the available options. This blog post draws the comparison between physical servers and virtual machines (VMs) by highlighting the main advantages and disadvantages which each of them provide.
What is a physical server?
The physical server vs virtual server comparison should start with the definition. A physical server, also known as a ‘bare-metal server,’ is a single-tenant computer server, meaning that a specific physical server is designated to a single user. The resources and components of a physical server are not shared between multiple users. Each physical server includes memory, processor, network connection, hard drive, and an operating system (OS) for running programs and applications. A bare-metal server is large in size due to the powerful processing components that it contains.
What is a virtual machine?
A virtual machine (VM) is a software computer used as emulation of an actual physical computer. A virtual server operates in a “multi-tenant” environment, meaning that multiple VMs run on the same physical hardware. In this case, the computing resources of a physical server are virtualized and shared among all VMs running on it. The architecture of a virtual server is a little more complex than that of a physical server. Thus, a hypervisor, such as VMware vSphere or Microsoft Hyper-V, is installed on top of physical hardware. A hypervisor is then used to create and manage VMs, which have their own virtual computing resources. After that, you can load multiple guest OSes and server applications on top of the virtual hardware. Thus, virtual servers allow you to run several OSes and applications on the basis of the shared physical hardware, which makes it a more cost-effective option than a physical server.
Comparing physical servers and virtual machines
To see the physical server vs virtual server differences, a closer look at all of their components is required.
This factor should be considered if your organization works with a large amount of data which needs to be constantly processed. Physical servers are far more powerful and efficient than VMs, due to the fact that VMs are prone to performance issues as a result of an overflow of virtual servers in a physical machine. Thus, a physical machine and a virtual machine, both having the same hardware and software resources and capabilities, cannot perform on the same level. If your organization runs operations which require the use of computing resources to the fullest extent, a physical server is the optimal choice.
As for the management factor, VMs are much easier to maintain than physical servers. In case of server failure, it could take several days to restore a physical server to its original state. For VMs, the recovery process can be initiated in just a few clicks with the help of modern VM backup software. Moreover, a physical server must be closely inspected for any deficiencies and, if required, additional drivers should be installed and set up before it can be used. This is not the case with VMs as they are built upon physical hardware which is ready for use. Thus, VMs can be created and powered on in a few minutes’ time.
However, managing a virtual server environment requires a high level of expertise and specific skills. Thus, make sure that the members of your IT team are competent enough to control your virtual infrastructure.
One of the major physical server vs virtual server differences lies in portability. You can easily move VMs across the virtual environment and even from one physical server to another, with minimal input on your part. This is due to the fact that VMs are isolated from one another and have their own virtual hardware, which makes a VM hardware-independent. Moving your physical server environment to another location is a more resource-intensive task. In this case, you will need to copy all data stored on the server to a removable media, transport the media as well as all hardware resources that you have to a new location, and then re-install all of the system components on a new server. Essentially, you will have to re-build a server from scratch.
To expand a physical server environment, you need to buy additional hardware components, which can be very expensive, and go through a long process of installation and configuration. At the same time, a virtual server environment provides the option of on-demand scalability. A single virtual server can host multiple VMs at the same time, which can be added or removed with the click of a mouse. Your virtual environment can be scaled up or down depending on the growth of your business needs. In this case, you don’t need to buy additional hardware to ensure VM deployment. This is due to the fact that VMs running on the host share the same computing resources, which can be evenly distributed among all VMs. Thus, you can design an easily configurable environment which can carry out operations of any complexity levels.
Physical servers do not use their hardware and software capabilities to maximum levels, with their average production capacity being at 25%. Thus, a lot of computing resources are left unused, which isn’t cost-effective. On the other hand, a server hosting multiple VMs takes care of underutilized resources by distributing them among other VMs which need it most. This way, optimum capacity management is achieved.
If the production site was hit by disaster, it is essential to quickly restore mission-critical data and operations so as to reduce system downtime and minimize its negative impact on business. It can take several hours or days to restore business operations running on a physical server. In this case, the disaster recovery (DR) process entails setting up a new physical server, installing an OS, setting up applications, and restoring critical data from backups.
The DR process in a virtual environment is much simpler. You can restore the entire VM at a DR site with the help of previously created VM backups, resulting in almost zero downtime. To ensure that the DR process runs smoothly and your data can be promptly recovered if needed, consider installing third-party data protection software, such as NAKIVO Backup & Replication. An efficient solution can offer you a variety of reliable data protection options for a fraction of the price.
Currently, businesses are expected to operate on an always-on basis, meaning that even a minor interruption in business operations can lead to major repercussions. Therefore, ensuring business continuity, especially in case of disaster, should be one of the main priorities of any organization.
When comparing physical servers and VMs, it becomes evident that VMs are more fault-tolerant. In case of disaster, the workload of your virtual environment can be transferred in a few clicks to another site, so as to ensure the minimum downtime. After the effects of the disaster have been mitigated and the production center has been restored, you can move the workload from the DR site back to the primary site.
If a disaster has affected or destroyed your physical server infrastructure, the damage, in most cases, is irreversible.
Security management is more easily configurable in a virtual server environment than in a physical one. With physical servers, you have to build a system of protection for each individual server, depending on its computing capabilities and resources and the sensitivity of data that it stores. This can be a resource-intensive task if your IT infrastructure is built upon 10 or more physical servers.
On the other hand, a virtual server environment can be protected on the basis of a universal security model. Thus, security policies and procedures can be developed, documented, and implemented from a single pane of glass – that is, through the hypervisor dashboard.
Building and maintaining a physical server environment can be quite expensive. This is due to constant hardware and software upgrades, frequent system failures, and breakdown of computer components and equipment, which are difficult or even impossible to repair.
At the same time, virtualization is considered a perfect option for enterprises which contain a large number of servers. A virtual server environment allows you to evenly distribute computing resources among all running VMs, thus ensuring capacity optimization for a minimal price. However, you should note that VM software licenses can be quite expensive as well. Depending on the size of the virtual environment, the price can be up to a few thousand dollars.
Physical servers vs. virtual machines: which one to choose?
As you can see, both physical servers and virtual machines provide users with multiple benefits. Therefore, when choosing between the two, it is important to consider their distinctive characteristics to find out how they can be applied to your organization’s infrastructure. The main differences between physical servers and VMs are outlined in the table below.
|Physical Servers||Virtual Machines|
|Large upfront costs||Small upfront costs|
|No need for licensing purchase||VM software licenses|
|Physical servers and additional equipment take a lot of space||A single physical server can host multiple VMs, thus saving space|
|Has a short life-cycle||Supports legacy applications|
|No on-demand scalability||On-demand scalability|
|Hardware upgrades are difficult to implement and can lead to considerable downtime||Hardware upgrades are easier to implement; the workload can be migrated to a backup site for the repair period to minimize downtime|
|Difficult to move or copy||Easy to move or copy|
|Poor capacity optimization||Advanced capacity optimization is enabled by load balancing|
|Doesn’t require any overhead layer||Some level of overhead is required for running VMs|
|Perfect for organizations running services and operations which require highly productive computing hardware for their implementation||Perfect for organizations running multiple operations or serving multiple users, which plan to extend their production environment in the future|
As you can see, physical machines and VMs are different from one another and, essentially, provide different benefits for organizations. Therefore, when deciding between the two options, you should clearly define the number of operations that your business executes, the performance level that your customers expect from the organization, and your business goals and objectives. Moreover, you should also consider such factors as the allocated budget, downtime tolerance, the amount of workload, data sensitivity, and the need for performance management. All these factors determine what your IT infrastructure needs to include for achieving high productivity and growth.
How to protect your VMs with NAKIVO Backup & Replication
As already mentioned above, the protection of your VMs can be improved by installing third-party data protection software. For this purpose, NAKIVO Backup & Replication is the perfect solution. The product provides image-based, application-aware backup and replication for VMware, Hyper-V, and AWS EC2 environments. NAKIVO Backup & Replication has introduced a number of features which provide multiple benefits for your VMs. Let’s take a closer look at them.
Advantages of NAKIVO Backup & Replication
Storage size reduction
To considerably reduce the storage size, NAKIVO Backup & Replication applies native change tracking technologies, such as Changed Block Tracking (CBT) for VMware and Resilient Change Tracking (RCT) for Hyper-V. These technologies allow you to identify the data that has changed since the last backup or replication, and update the backup repository only with new data.
NAKIVO Backup & Replication enables the exclusion of swap files or partitions from VM backups. Moreover, the built-in features of data compression and deduplication ensure that the storage space isn’t filled with duplicate copies of repetitive data. Compression shrinks the size of each data block, whereas deduplication ensures that only unique data blocks are saved. When you create a new backup repository, the compression and deduplication features are enabled by default.
NAKIVO Backup & Replication also includes the feature of Transaction Log Truncation for Microsoft SQL Server and Microsoft Exchange. The product truncates (removes) the transaction logs after running VM backup or replication jobs.
Enhanced data transfer
Moreover, NAKIVO Backup & Replication includes the LAN-free data transfer mode which includes Hot Add or Direct SAN Access features. With the Hot Add feature, you can mount VM snapshots and read VM data directly from the VM datastore through the storage I/O stack, without involving the host’s TCP/IP stack. With the Direct SAN Access mode, you can read VM data directly from a SAN storage device over or iSCSI Fiber Channel. These transport modes allow you to significantly increase the data transfer speed and reduce the load on the production network.
With NAKIVO Backup & Replication, you can improve the WAN transfer speed, which is possible through the network acceleration feature. By applying data compression and traffic reduction techniques, the network can be optimally used to achieve faster VM recovery and improve the speed of backup and replication jobs.
Another feature that allows you to enhance data transfer is Advanced Bandwidth Throttling. With bandwidth throttling, you can set data transfer speed limits for jobs running in the virtual environment. This way less LAN/WAN bandwidth is consumed. Moreover, you can set up different schedules for the implementation of throttling rules. Overall, this feature allows you to have full control over your network traffic.
Disaster recovery automation
Apart from running backup and replication jobs, NAKIVO Backup & Replication has also introduced the Site Recovery feature, which has considerably simplified the DR process. The solution allows you to create site recovery workflows which can include a number of actions and conditions arranged in an order of your choice. This way you can set up an automated algorithm of any complexity which is based on your DR plan. You can create site recovery workflows which can be executed in the following cases: planned failover, emergency failover, failback, datacenter migration, etc. After the initial configuration, a site recovery job can be run in a few clicks. Thus, you no longer need to manually monitor the DR process and can devote time to dealing with other issues during a DR event.
If you are running a multi-platform environment, check out the Cross-Platform Recovery feature, which allows you to export VM disks across platforms in the format of your choice.
NAKIVO Backup & Replication is also a reliable data protection solution, which has a set of features designed specifically for security purposes. One of them is Self-Backup, which provides automated protection of the configurations that you have previously adopted. Thus, if the VM running the product has failed or was deleted, you can quickly install a new instance of NAKIVO Backup & Replication and restore the system configuration (jobs, settings, backup history, inventory, etc.) from a self-backup. Self-backups are performed on a daily basis and the copied configuration data is then sent to a backup repository.
Moreover, you can set up the Screenshot Verification feature, which takes OS screenshots of test-recovered VMs. This way you can receive proof of VM recoverability, which is crucial for successful recovery.
Apart from that, NAKIVO Backup & Replication can guarantee that your data is constantly protected. The product applies AES 256-bit encryption for protecting VM data, which is a data/file encryption technique used worldwide. NAKIVO Backup & Replication ensures that the VM data sent over the WAN is encrypted before the beginning of data transfer (encryption in flight). The data stored in the backup repository is also encrypted so as to protect the VM data from unauthorized access and hacker attacks (encryption at rest).
Ease of use
NAKIVO Backup & Replication is an easy-to-use solution, which boasts a simple and intuitive web interface. Thus, you can start managing VM data protection from anywhere with a single click of the mouse. A web-based user interface includes the following components which ensure management optimization:
- Calendar Dashboard. This feature is used for viewing all past, current, and future backup and replication jobs. All information is displayed in the form of a calendar.
- Live Chat with Tech Support. You can communicate with our support team in real time, without leaving the product interface.
- Flexible Job Scheduler. You can assign several schedules to a single job based on your needs.
- Global Search. This feature is helpful in managing large-scale environments as it allows you to easily find any job, VM, backup, replica, or backup repository and perform necessary actions on them.
The latest addition to the product toolset is the Policy-Based Data Protection feature, which was introduced with NAKIVO Backup & Replication 8.1. This feature allows you to set up policies for protecting specific VMs which match policy rules. Thus, you don’t need to manually monitor each VM and ensure its protection as the process is completely automatic and requires minimal input on your part. Policies can be created for VM backup, backup copy, and replication jobs based on the selected criteria (e.g., a VM’s name, size, tag, etc.). Thus, the product can automatically include VMs to data protection jobs if they match the policy rules.
NAKIVO Backup & Replication is considered one of the most affordable data protection solutions on the market. The product includes a variety of built-in features which allow you to significantly improve the data protection capabilities of your system. With NAKIVO Backup & Replication, you can get a full-fledged data protection toolset for a fraction of the price of competitors’ offerings.
Deciding between physical machines and VMs can be difficult, but defining your business needs and goals and considering the resources available within your infrastructure can be of great help. The introduction of virtualization has completely changed the way businesses conduct their operations. Even though physical servers are still widely used, virtualization has introduced many advantages and attracted a huge following over the years.
Based on the comparison drawn in this blogpost, it is safe to say that creating a virtual server environment provides a greater quantity and array of benefits and opportunities for your organization. Despite that, you should still choose the server environment that would work best for you and your business, be it physical or virtual servers. Many organizations now give preference to a hybrid server environment as it allows to combine the capabilities of the powerful server hardware with the benefits of virtualization.
NAKIVO Backup & Replication is a fast, reliable, and affordable data protection solution which can securely protect virtual environments of any scale. The product is constantly developing and adding new features, which allows NAKIVO Backup & Replication to provide its customers with a high level of services.