What is a disaster recovery site?
A disaster recovery (DR) site is a secondary site which stores a backup of data from the primary site, and takes over computer processing in the case of a disaster. A disaster could be anything that prevents the primary site from functioning, for example a natural disaster damaging the data centre or a cyber attack. There are three types of DR sites – cold, warm and hot. A DR site is central to a DR strategy – for more details on the benefits of a strategy and what to consider, read our insight ‘What is Disaster Recovery?’.
What is a warm disaster recovery site?
Understanding a warm disaster recovery (DR) site requires comparison to cold and hot DR sites.
Cold DR site
A secondary data centre or backup facility consisting of basic power, network capability and cooling. Backup data is sent to the site and installed. A cold site takes the longest time to resume business operations after a disaster.
Warm DR site
A warm DR site contains the elements of a cold site, and additionally has network connectivity, meaning data can be synchronised daily or weekly from the primary site. It is not real-time, so updates are not instant. There is less operational capacity than the primary site. In the event of a disaster, the warm site is booted up and takes over from the primary site using the latest backup data. Due to the time to boot the site, there will be a small amount of downtime – this is known as near-time recovery.
Hot DR site
A hot DR site is a full mirrored copy of the primary site, with real-time replication meaning updates are instant and backups are complete. The site is always live, so in the case of a disaster, failover is instant, with virtually no downtime.
Warm DR takes a middle ground between cold and hot DR, giving a more thorough and resilient solution than cold DR, but with more downtime and risk of data loss than hot DR.
How long does Warm Disaster Recovery take?
There are two concepts to consider when looking at the length of time warm DR takes:
- RPO – The Recovery Point Objective (RPO) defines the point in the server’s timeline you can return to after a disaster, and the amount of data loss you can tolerate. The closer to real-time replication your solution is, the lower your RPO, and the less data loss you risk. Hot DR has the lowest RPO as it uses continuous replication. Warm DR uses near-time replication, so has a low RPO but some risk of data loss. Cold DR has the lowest RPO and has the largest risk of data loss.
- RTO – Recovery Time Objective (RTO) is the maximum amount of time that it takes to recover from a disaster. Warm DR has a higher RTO than hot DR due to time needed for the secondary site to be booted up before failover.
The RPO of a warm DR solution can be flexible, depending on your tolerance to data loss. The solution can be configured with backup/synchronisation to the secondary site anywhere from once a day, to almost instantaneous. As a general rule, a lower RPO will require more server resources and will come at an increased cost. This potential for increased cost should be weighed against the potential business cost of data loss.
Is warm disaster recovery the right plan for me?
Working out which kind of disaster recovery (DR) site your business needs requires careful planning.
Disaster Recovery (DR) shouldn’t be seen as a ‘luxury’ add-on service solely for larger companies, but a fundamental part of every IT strategy. This is why different types of DR recovery sites are available which reflect how closely the DR environment needs to match live operations.
When choosing your DR plan, you should consider:
- Tolerance for downtime – How would downtime affect your business, customers and day-to-day business operations? A hot DR site offers instant failover, meaning there will be no downtime, whereas warm DR does have a small amount of downtime as the site needs to be booted up on demand. Warm DR is best suited to businesses who need to maintain uptime, but it is not critical to the ongoing operation of their business.
- Tolerance for data loss – With both cold and warm DR there is some capacity for data loss as backup of data is not real-time. This can be minimised in warm DR through more frequent backups/synchronisation. If your business cannot tolerate any data loss, the real-time replication in hot DR would be more suitable.
- Budget – Compared to hot DR, where the secondary site is always live, a warm DR site can be a more affordable option, as you do not have two live sites at the same time.
- Testing – Warm DR can be more difficult to test, as the secondary site will need to be booted up for testing. With hot DR, the site is always live, so can be tested at any time.
Warm DR is well suited to a business with a lower budget and a requirement for flexible and fast recovery. If however your business has zero tolerance for downtime and data loss, a hot DR solution would be more suitable.
Why choose Hyve for disaster recovery services?
We have experience running DR solutions for a range of businesses across sectors. With so many options on the market, and the potential business consequences of an insufficient DR strategy, our experts can guide you on the best solution for you.
We operate Warm and Hot DR solutions, hosting certified and compliant secondary sites for your business. Our DR solutions use industry-leading technologies Veeam, Nakivo, Zerto and Doubletake, and we can also failover to Azure, AWS or Hyve clouds.
Using a third-party provider such as Hyve for your DR means you do not need to invest in or maintain your own off-site DR environment. You can be assured that our dedicated Technical Support Engineers will always be on hand to assist in failover and recovery and will work with you until you achieve full system recovery.
You can find full details of our Warm DR solution on our dedicated Disaster Recovery page.
Does your business need a warm DR strategy?
Our cloud experts can set up an initial consultation to assess your options – fill out our contact form and we will be in touch.
