What Is VM Sprawl and How to Prevent It
Virtualization allows you to create a number of virtual machines on a single physical server. This technology provides several advantages, including enhanced utilization of hardware resources, scalability, and increased flexibility.
Creating virtual machines (VMs) is also easier and faster than deploying physical servers. As a result, the number of VMs can grow quickly. Without proper management and oversight, organizations may create and deploy such a large number of virtual machines that it becomes difficult to track and manage them, resulting in VM sprawl. Let’s look in more detail at what it is and how to control and prevent VM sprawl.
What Is VM Sprawl?
Virtual machine sprawl is a situation in which the number of VMs in a virtualized environment grows so rapidly that it becomes difficult to manage and control those VMs effectively. When an administrator can no longer manage the VMs effectively, you end up with wasted resources, increased complexity, and decreased efficiency.
VM sprawl is a common situation with testing or software development. For example, a virtual machine may be created to test Or to develop software. Later, when work is done with a particular VM, it becomes unused but continues to consume processor and memory resources on a hypervisor server (if the VM is running) and disk space (even if the VM is powered off). Now imagine the scenario when a company has dozens of abandoned VMs. As a result, employees may forget about these existing VMs and create new ones for their subsequent tasks.
What is system sprawl?
System sprawl refers to the uncontrolled proliferation and expansion of hardware and software systems within an IT environment. This happens as a result of rapid and unchecked growth of various systems, servers, applications and services, leading to complexity, inefficiency, and increased administration complexity.
What is server sprawl?
Server sprawl refers to the uncontrolled proliferation of physical servers within a data center or IT infrastructure. It occurs when organizations deploy and maintain an excessive number of servers, often without proper consolidation or resource optimization.
Issues Caused by VM Sprawl
VM sprawl can lead to several issues in an IT environment, which become a challenge for organizations, including:
- Resource waste. Underutilized or unused VMs consume resources such as CPU, memory, storage, and network bandwidth. This is an inefficient use of hardware resources within the IT infrastructure. This inefficiency increases costs by requiring additional hardware resources and impacts overall system performance.
- Performance degradation. VM sprawl can result in resource contention, where multiple virtual machines compete for limited resources on the underlying physical server or storage infrastructure. This contention can lead to performance degradation and slower response times for critical applications and services, impacting user experience and productivity.
- Increased management complexity. As the number of virtual machines grows uncontrollably, managing and monitoring them becomes more complex and time-consuming. You may struggle to keep track of VM configurations, updates, security patches, and compliance requirements. The lack of visibility and control can lead to operational inefficiencies and difficulties in troubleshooting issues.
- Scalability challenges. VM sprawl impacts negatively on the scalability of your IT infrastructure. The excessive number of virtual machines can prevent you from adding or allocating resources as needed. Scaling up or accommodating new applications becomes cumbersome, requiring provisioning and configuration adjustments across a large number of virtual machines.
- Licensing and compliance challenges. Each virtual machine may require licenses for operating systems, applications, or other software. With VM sprawl, it becomes difficult to keep track of the number of licenses used and ensure compliance with software licensing agreements. This can result in unexpected costs or non-compliance issues.
- Increased costs. VM sprawl drives up operational costs in several ways. It requires additional hardware to support the VMs, resulting in increased expenditure. Moreover, the ongoing power consumption, cooling, and maintenance costs also rise. Licensing costs may increase due to the larger number of operating system licenses or application licenses required. Unused VMs can consume paid licenses.
- Backup and disaster recovery complexities. Managing backups and ensuring proper disaster recovery becomes more challenging with a large number of virtual machines. Backup scheduling, storage allocation, and recovery procedures become more complex, potentially leading to increased downtime with difficulties in recovering critical data. When backing up unneeded VMs continuously, backup storage consumption, network load together with CPU and memory load increase.
VM Sprawl Security Risks
The most common security risks associated with VM sprawl include:
- Unauthorized access. With a large number of virtual machines, it becomes challenging to track and manage user access to each VM. This increases the risk of unauthorized users gaining access to sensitive data or systems if proper access controls are not in place.
- Unpatched systems. With a sprawling VM environment, applying security patches and updates to each VM can become difficult to manage. Unpatched VMs may have vulnerabilities that are known by attackers and can be exploited to gain unauthorized access or compromise the overall system.
- Inadequate security configurations. VM sprawl can lead to inconsistent security configurations across VMs. If security controls such as firewalls, intrusion detection systems, or antivirus software are not uniformly applied or updated, it creates potential vulnerabilities that can be exploited by attackers.
- Data leakage and loss. With a large number of VMs, the potential for data leakage or loss increases. Improper configuration or weak security controls on VMs can expose sensitive data, leading to data breaches or unauthorized disclosure.
- Inefficient monitoring and logging. Managing security events and monitoring logs across too many VMs is complicated. Without centralized monitoring and proper log management, detecting security incidents or anomalies may be challenging, delaying response and mitigation efforts.
- VM escape. In certain scenarios, attackers may attempt to exploit vulnerabilities within a virtual machine to break out of its isolated environment and gain unauthorized access to the underlying hypervisor or other virtual machines. VM sprawl can exacerbate the risk of VM escape if proper security controls are not implemented.
How to Prevent VM Sprawl?
You should be aware that VM sprawl can occur gradually, before all the hardware resources of servers (hypervisors) are fully loaded. It is difficult to resolve issues caused by VM sprawl when there is no longer any free storage space or CPU and memory capacity.
Preventing VM sprawl requires proactive management and the implementation of strategies to control the proliferation of virtual machines. Follow these key recommendations to prevent VM sprawl:
- Define and enforce policies and guidelines for creating, managing, and decommissioning virtual machines. These policies should outline the process for requesting and provisioning virtual machines, resource allocation guidelines and decommissioning procedures. The policies should be communicated to all stakeholders and consistently enforced.
- Implement a VM lifecycle management process. This includes regular audits to identify unused or obsolete virtual machines, monitoring VM resource utilization and ensuring proper decommissioning of VMs that are no longer needed.
- Implement regular capacity planning to anticipate resource needs and allocate resources accordingly. Estimate the right size for each VM. This helps prevent overprovisioning and ensures that resources are available when needed.
- Standardize VM configurations and templates that meet the requirements of different applications and services. By promoting the use of standardized configurations, you can streamline management and reduce the risk of inconsistent security settings or misconfigurations.
- Use clear naming for VM identification. Ask users to name VMs in a way that includes the department name and/or purpose of VMs. For example, a VM name like Ubuntu22 or Windows7 doesn’t allow you to understand who the VM owner is or its purpose. In contrast, a VM name like Ubuntu22-WebTest, Windows7-MarzenaK or Server2016Ora12Dev is easier to understand. Always add the details about a VM in the VM description field rather than using long names. You can use tags as well.
- Monitor resource utilization. Deploy monitoring tools to track resource usage across VMs. Regularly review resource utilization metrics to identify underutilized or overprovisioned VMs. These tools help track VM deployments, resource utilization, and compliance with policies. Real-time monitoring alerts can identify abnormal resource usage and help in terms of VM sprawl avoidance as well as identify and delete unused VMs.
- Regularly review and optimize VM deployments to identify and decommission unnecessary or inactive VMs. Assess the business need for each VM and ensure that VMs are properly aligned with current requirements. Regularly assess and improve VM management processes and policies based on feedback, lessons learned, and changing business needs.
- Educate users and administrators. Provide training and education to users and administrators about the impact of VM sprawl, the importance of efficient resource utilization, and the proper procedures for VM provisioning, management and decommissioning. Educate them about the benefits of efficient VM usage and the importance of following established policies, VM sprawl preventing best practices, common security threats and how to respond to security incidents.
- Recycle inactive VMs. After identifying unused and abandoned VMs, delete them to free up hardware resources. Delete redundant VM snapshots because they cause additional storage consumption.
Note: Try always to inform users when you are going to delete VMs. While temporary VMs are common in the working process, there can be other situations. Some users may have important information on forgotten VMs and should copy this information before the VM is deleted. Users can use some VMs irregularly with strikes of activity. If you are not sure that a VM is without the owner, you can back up / archive the VM and delete the VM from a datastore. Later, if this VM is not needed after time has passed (for example, a few months), you can delete the VM backup completely from a backup repository.
The Best Security Practices
To minimize the negative impact of VM sprawl on security, it is important to implement the best security practices. Consider the following key security practices.
- Employ the least privilege principle. Adhere to the principle of least privilege by allocating users and applications with only the essential permissions and privileges needed to carry out their designated tasks. Avoid giving excessive administrative access to virtual machines.
- Implement strong access controls. Establish robust access controls to virtual machines, including strong authentication mechanisms and role-based access control (RBAC). Restrict access to authorized individuals or groups and regularly review and revoke unnecessary privileges.
- Regularly patch and update virtual machines. Implement a rigorous patch management process to ensure virtual machines are up to date with the latest security patches and updates. Regularly apply patches to address known vulnerabilities and minimize the risk of exploitation.
- Harden virtual machine configurations. Apply security hardening guidelines and best practices to virtual machine configurations. This includes disabling unnecessary services and protocols, configuring strong passwords and enabling appropriate firewall rules.
- Use virtual machine templates and secure baseline images. Create secure baseline images or templates for virtual machines. These images should have preconfigured security settings and hardened configurations. Utilize these templates for deploying new virtual machines to ensure consistent security configurations.
- Implement network segmentation. Employ network segmentation to isolate virtual machines based on their security requirements. Utilize virtual local area networks (VLAN or VXLAN) or virtual firewalls to restrict network traffic between virtual machines and enhance security boundaries.
- Implement network monitoring and intrusion detection systems. Deploy network monitoring and intrusion detection systems (IDS) to detect potential security breaches or abnormal network activities and respond to them. Monitor network traffic between virtual machines and identify suspicious behavior or unauthorized access attempts.
- Regularly audit and review virtual machine configurations. Conduct regular audits and security reviews of virtual machine configurations. This helps identify misconfigurations, non-compliant settings or security vulnerabilities. Remediate identified issues promptly to maintain a secure VM environment.
- Implement centralized logging and monitoring. Set up centralized logging and monitoring solutions to collect and analyze logs from virtual machines. This enables quick detection of security incidents, abnormal behavior or unauthorized access attempts.
- Conduct vulnerability assessments and penetration testing. Regularly perform vulnerability assessments and penetration testing on virtual machines to identify potential security weaknesses. Address identified vulnerabilities and ensure that virtual machines are adequately protected against attacks.
- Continuously monitor and improve security. Implement continuous monitoring and improvement processes to stay updated with the latest security threats and best practices. Regularly review and update security policies, procedures and technologies to adapt to evolving security challenges.
By following these security practices, you can minimize the negative impact of virtual machine sprawl on security, protect sensitive data and maintain a secure virtualized environment. Follow the best practices for VM sprawl avoidance and security best practices to minimize security risks related to VM sprawl.
VM Sprawl vs VM Escape
VM escape and VM sprawl can cause heavy troubles in virtual environments. Let’s explain what VM escape is and find out the difference between these two terms.
What is VM escape?
VM escape, also known as hypervisor escape, is an exploit that takes advantage of a security vulnerability whereby an attacker gains unauthorized access to the underlying hypervisor from within a virtual machine. In other words, it involves breaking out of the isolated VM environment and compromising the host hypervisor or other VMs running on the same physical server.
VM escape typically occurs due to a vulnerability or misconfiguration in the virtualization software or the underlying hypervisor. An attacker can exploit this dangerous vulnerability and execute malicious code or manipulate the VM’s resources to gain elevated privileges or access to the hypervisor’s functionality. VM escape is a serious threat to VM security. Make sure to install security patches in time for VM escape protection.
The difference between VM sprawl and VM escape
VM sprawl and VM escape are two distinct concepts related to virtual environments, but they involve different aspects and risks. VM sprawl refers to the uncontrolled growth and excessive deployment of virtual machines, leading to inefficiencies and management challenges. On the other hand, VM escape is a security vulnerability where an attacker breaks out of a virtual machine to compromise the underlying hypervisor and potentially other VMs. While VM sprawl focuses on the management and resource optimization aspects, VM escape pertains to the security risks associated with virtualized environments.
Conclusion
VM sprawl can negatively impact the IT infrastructure’s performance, resource utilization, scalability and cost efficiency. It can also introduce security risks, create compliance challenges, and complicate backup and disaster recovery processes. Controlling VM sprawl and implementing effective management strategies is crucial to mitigate these impacts and ensure a more optimized and efficient IT environment for the business.
Stay informed about emerging technologies and trends in VM management to optimize resource utilization and prevent VM sprawl. Don’t forget to back up VMs in your infrastructure. NAKIVO Backup & Replication provides image-based, app-aware backup of VMs for swift recoveries of full machines or the needed application objects.
