Disaster Recovery: Warm Site vs Cold Site vs Hot Site

Alternate sites or facility are required as part of DR strategy to enable recovery and operation during a prolonged disaster situation. There are three major types of disaster recovery sites introduced in this article: cold, warm, and hot sites.


By Crystal / Updated on March 8, 2023

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Types of disaster recovery sites: cold, warm, and hot sites

When servers go down because of a natural disaster, equipment failure or cyber-attack, Disaster Recovery will extract critical business data from this secondary site and recover lost data to primary servers, which ensures minimal data loss and business continuity. Meanwhile, one of the key elements in any Disaster Recovery plan is the selection of a secondary site for data storage. There are three major types of disaster recovery sites:

  • Cold site for disaster recovery
  • Warm site for disaster recovery
  • Hot sites for disaster recovery

Understanding the differences among these three can help SMBs, working in cooperation with an expert IT consultant, to select the one that best suits company needs and mission-critical business operations. The characteristics for each of these sites will be discussed in the following sections.

disaster recovery site

What is a Cold & Warm & Hot site for disaster recovery

How to choose a disaster recovery site? It depends on the desired RTOs and RPOs i.e., how much downtime and data loss is acceptable or affordable.

Tips: RTO is the time from the occurrence of the disaster to the time the systems are functioning again. RPO indicates how far back in time you can go in case of a disaster and the amount of work and/or transactions you can afford to lose without affecting business continuity.

Cold Site for disaster recovery

A cold disaster recovery site has fewer facilities, so it’s the cheapest option for not having equipment set up and running, but it will take more time to get your site back online. This environment might sometimes be used for dev/test and can be repurposed for DR at a time of need.

Warm Site for disaster recovery

Warm Site is the balance of both hot and cold sites. It’s configured with system hardware, software, power source, phone, network etc., and it may have servers and other resources. The infrastructure exists and is running, but intermittently, so a Warm Site for disaster recovery is not ready for immediate switch over.

Hot Site for disaster recovery

Hot Site is a fully functional backup site that work 24 hours a day, seven days a week, and the data in the servers are continuously being backed up through the hot backup method. The entire environment is already up and running.

The business who are highly dependent on their data prefers hot site to restore data with minimum time, which reduces business downtime and data loss. However, operating a hot site is almost like running two systems at the same time, and hence they increase company costs substantially.

what is a warm site for disaster recovery

The significance of virtualization for Warm Site

Virtualization helps to make systems available quickly in case of an emergency, as the entire virtual machine can be backed up. This allows an organization to boot machines that have been backed up in a completely different environment without having to worry about hardware compatibility. Previously at hot, warm and cold sites, the hardware would be the same as at the production site to avoid potential compatibility issues during recovery. This can be very expensive for an organization.

With virtualization, however, the hosts that house the virtual servers can have different hardware than the production system without compatibility issues because the hardware presented to each virtual machine is the same. The hosts do this through a process called abstraction, in which the virtual machines are presented with resources in a generic way, but these resources are managed by a service called a behind-the-scenes hypervisor.

Therefore, you may perform virtual machine backup & recovery to ensure that the data is safe and easily accessible for business continuity.

Build disaster recovery plans with hot virtual machines backup

To back up multiple VMware or Hyper-V VMs while running to ensure business continuity, I would recommend you a free virtual machine backup software - AOMEI Cyber Backup. With its concise and centralized console, you can schedule hot backups for VMs and schedule the backup plan automatically. Besides, it's easy to restore a VM from any selected backups. Just try it to enjoy the following benefits:

Hot backup: perform hot VM backup automatically for multiple virtual machines without any downtime.
Restore from any point: easily restore a VM from any selected backup files.
Fast recovery: based on clicks, you can restore a VM to its previous state quickly.
Perpetual free: no time limit for AOMEI Cyber Backup Free Edition.
Support Free ESXi: support both paid and free versions of VMware ESXi.

Simply hit the button below to download and use AOMEI Cyber Backup Free Edition:

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*You can choose to install this VM backup software on either Windows or Linux system.

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An ideal disaster recovery site minimizes the effects of a disaster for the organization. This article describes what is a Warm Site for disaster recovery and compare the differences among cold site, warm site and hot site. According to your desired RTO and RPO, you can choose a suitable disaster recovery plan with proper cost.

Crystal · Editor
Crystal is an editor from AOMEI Technology. She mainly writes articles about virtual machine. She is a positive young lady likes to share articles with peolpe. Off work she loves travelling and cooking which is wonderful for life.