Hot and cold storage are colloquial industry terms for storage tiers, which differ based on the frequency at which data is accessed. Is data “hot” (moving around regularly) or “cold” (generally stagnant)? Most businesses have both types of storage—data they need to process frequently, and data that can sit for long periods of time without a second glance. This guide to hot and cold storage covers the benefits and use cases of each type of storage tier as well as the importance of storage tiering overall.
Hot Storage Overview
Hot storage holds frequently accessed data. It often supports critical business applications like security tools and databases.
Because hot storage requires technology that can quickly retrieve data, like flash-based drives, it’s typically more expensive than colder storage tiers. Flash is a newer technology than spinning disk or tape, and while its prices have somewhat stabilized over the past couple decades, it is usually still pricier overall.
For most large enterprises, flash is a necessary expense to support critical workloads. Keep in mind that because hot storage is more expensive and often supported by partial or all flash, it’s more difficult to store large sets of data in hot or warm tiers. Warm storage falls between cold and hot—not archive data, but not as readily accessible as hot storage either.
Hot Storage Use Cases
While by no means an exhaustive list, the following use cases for hot storage support important business operations and require quick access to stored data.
Back-end security systems
Cybersecurity data is one of the most important use cases for hot storage. While some security data can certainly be archived, most of a security team’s day-to-day applications—like endpoint protection programs and threat monitoring tools—need data available constantly. This is especially critical when a breach occurs and rapid access can mean the difference between millions of dollars lost or retained.
CRMs and other customer management tools
Customer relationship management software like Salesforce is often one of the most critical tools for sales teams. They have to use it for calls with customers, follow-ups, sales strategy, and report creation. All the relevant customer data must be available every day whenever it is needed. Sales teams can’t sit and wait for an archival database to load—they need that information immediately.
Databases that store data for mission-critical workloads typically require a hot storage tier so they can immediately pull data when queried. Keep in mind that some databases would be better suited to cold storage. It depends entirely on the type of workloads the database supports.
Data analytics and big data operations
Data analytics platforms like Tableau and Sisense process huge volumes of data. Similarly, some of the reports created by big data solutions like SAS and Qlik require real-time data. Hot storage makes that data available as soon as possible, enabling more up-to-date business analytics and reports.
Cold Storage Overview
Cold storage tiers store data for long periods of time, at lower costs than rapid-access data. Some cold storage can even be taken offline—typically tape and hard drives. This is a cybersecurity benefit, as data is much harder to reach when it’s not exposed to malware or the internet. Rapid restoration for cold storage is rare.
Cold storage typically costs less than hot or warm storage. It’s considered an archival solution, and because it doesn’t require the energy or computing power of rapid-access storage like non-volatile memory express-based flash (NVMe), it’s cheaper.
Cold storage is particularly beneficial for organizations required to store data for long periods of time, regardless of whether that data is frequently accessed or not. Storing massive volumes of data is expensive, so choosing low-cost solutions that can handle large data sets is the best way to save money. Cold storage is cheaper overall and suitable for long-term data storage.
Learn about cold data storage in cloud environments.
Cold Storage Use Cases
Two of the most important uses of cold storage are storing long-term data and preserving large sets of data for analytics.
Storing regulatory data at low costs
Organizations in industries like financial services, healthcare, and legal may be required to store data safely for years. In some cases, regulations like the European Union’s General Data Protection Regulation (GDPR) or the Health Insurance Portability and Accountability Act (HIPAA) mandate that customer data is retained for a specific period. Businesses must also make this data available to authorities upon demand in a legal situation. This can result in huge volumes of data being stored for many years—placing this data in cold tiers reduces some of the inherent expenses of bulk storage.
Storing large data sets for analytics
Cold storage tiers are beneficial for preserving large volumes of raw data for potential analysis. Note that this type of analytics data is different from real-time analytics workloads, which are better supported by hot storage. In this case, the data is archived and saved for future analytics. Although your business may not know when exactly it will need a particular data set for analysis, it’s there when you do.
What is Storage Tiering?
Storage tiering is the organization of data based on how often your business needs it. The most common tiers include:
- Hot storage—best for rapid data access
- Warm storage—best for older data that still needs to be readily accessible
- Cool storage—best for on-site data storage that can be either online or offline
- Cold storage—best for rarely accessed data
Effectively managing storage includes ensuring that you don’t waste money by storing data somewhere it doesn’t need to be. For example, data sets that are only accessed twice a year don’t need to be in a hot tier. This doesn’t make sense financially.
Effective storage tiering requires regular inventory. Storage and IT teams must keep diligent track of what data their business applications use, and with what frequency. This allows them to appropriately organize data sets and store them in the proper location.
Some storage systems tier data automatically, like cloud buckets. This improves efficiency—if the cloud storage solution detects that a customer isn’t accessing data frequently, it might be bumped to a cooler tier automatically, reducing the manual workload of storage administrators.
Bottom Line: Which Should You Choose?
Hot and cold storage are not mutually exclusive—many enterprises will need both a hot and a cold storage solution. Data needs are diverse, and so are the applications that data supports. To save money, your storage team should know what each application needs and tier data accordingly.
For customer-facing applications and back-end software tools that need to immediately query data, choose a hot tier. For large volumes of regulatory or other archive data, choose a cold tier with low fees and strong security controls. The right storage solution will help your business’s budget, storage teams, and customers.
Read more about the benefits and use cases of storage tiering.