Cloud backup, also known as online backup, is a strategy for backing up data that involves sending a copy of the data over a proprietary network to an off-site server. The server is usually hosted by a third-party service provider, which charges the backup customer a fee based on capacity, bandwidth or number of users. In the enterprise, the off-site server might be owned by the company, but the chargeback method would be similar. Implementing cloud data backup can help bolster an organization’s data protection strategy without increasing the workload on information technology staff.
How cloud backup works
The backup process copies data and stores it on different media or another storage system for easy access in the event of a recovery situation. Cloud backup serves this purpose for many organizations.
Options for cloud backup services include:
- Backing up directly to the public cloud. This method entails writing data directly to cloud infrastructure providers, such as Amazon Web Services (AWS) and Microsoft Azure.
- Backing up to a service provider. An organization writes data to a cloud service provider with backup services in a managed data center.
- Cloud-to-cloud backup. For data that lives in the cloud in software as a service (SaaS) applications, this practice copies that data to another cloud.
When an organization begins to use cloud backup services, the initial backup can sometimes take days to finish uploading over a network due to the volume of data to be transferred. A technique called cloud seeding enables a cloud backup vendor to send a storage device, such as a disk drive or tape cartridge, to the organization, which then backs up data locally and sends the device back to the provider. That removes the need to send the initial data over the network to the backup provider. After the initial seeding, only changed data is backed up over the network.
How data is restored
Online backup systems are typically built around a client software application that runs on a schedule determined by the purchased level of service. If the customer has contracted for daily backups, for instance, the application collects, compresses, encrypts and transfers data to the cloud service provider’s servers every 24 hours. To reduce the amount of bandwidth consumed and the time it takes to transfer files, the service provider might only provide incremental backups after the initial full backup.
Cloud backup services often include the software and hardware necessary to protect an organization’s data, including applications for Exchange and SQL Server.
Cloud backup benefits
Cloud backup benefits include:
- There are reduced costs if the volume of backup data is low.
- The cloud is scalable. Growing datasets are easily backed up in the cloud. But organizations need to be wary of escalating costs as data volume grows.
- Managing cloud backups is simpler, as service providers take care of many of the tasks that are required with other forms of backup.
- They are generally secure against ransomware attacks because they are performed outside of the office network.
Cloud backup vs. tape and disk
In the enterprise, cloud data backup services are primarily used for noncritical data. Traditional backup is a better offering for critical data that requires a short recovery time objective (RTO) because there are physical limits as to how much data can be moved in a given amount of time over a network. When a large amount of data needs to be recovered, it may need to be shipped on tape or some other portable storage media.
Tape backup requires data to be copied from a primary storage device to a tape cartridge. Cartridges have grown dramatically in capacity in recent years. LTO-8 tapes, released in late 2017, can store 12 TB of uncompressed data and 30 TB compressed. Tape is a strong storage medium in an age of exponential data growth. In addition to their capacity benefits, tapes are comparatively inexpensive to own and operate. However, the restore process can be slow because access is sequential.
While the cloud appears to offer unlimited capacity, costs rise dramatically depending on how much storage an organization needs. While access is not sequential like with tape, restore times are still dependent on the internet and require an appropriate amount of bandwidth. Cloud service providers take some of the backup management work out of the process for organizations. The process of backing up to tape and maintaining the cartridges is essentially up to the organization. There is more flexibility in the process of restoring from cloud backup, as an organization can restore to several different devices, including laptops and phones.
The cloud and tape both provide protection from cyber attacks, such as ransomware. Cloud backups are useful in the event of an attack because they are off-site. Tape backups are even more secure because they are offline.
Disk, while not as portable as tape, is a common medium for backup. The biggest benefit is access speed. Disks offer random access and often top cloud and tape for restore speed. Disk-based backups are typically performed continuously throughout the day, while tape backs up less regularly. Disk-based backup is self-contained, and there is less personal interaction than with tape. So, the risk of human error is smaller. Disk-based backup can be expensive, often costlier than tape or cloud. The lifespan of a disk is shorter than tape, and its durability is weaker than that of tape. As long as the service provider is still in business, the lifespan of a cloud backup could be longer than that of disk or tape. With a proper retention policy, cloud backups can reduce or even replace the need for off-site tape storage, so organizations are making the switch from disk-to-disk-to-tape (D2D2T) strategies to disk-to-disk-to-cloud (D2D2C).
Cost of cloud data backup
Third-party cloud backup has gained popularity with SMBs and home users because of its convenience. The technology has an initial upfront cost to implement, but its lower monthly or yearly payment plans appeal to many smaller operations. Capital expenditures for additional hardware are not required, and backups can be run dark. However, the cost of keeping data in the cloud for years does add up. In addition, costs rise as the amount of data to be backed up to the cloud increases.
Security is an important element in the process. Three considerations are often referred to as the security CIA: confidentiality, integrity, and availability.
Since most data will move across the public internet on its way to the cloud, for confidentiality, many cloud backup providers encrypt data throughout the process: at the original location, during transit and at rest in the provider’s data center. A user or the provider holds the encryption key. Most organizations prefer to hold their encryption keys, and providers should offer this option. Types of network encryption include Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols.
For integrity, users must determine if data is the same when it is read back or if it was corrupted. Object storage offers built-in integrity checks.
Availability takes the restore process into account: Will data be available in a timely fashion in a disaster recovery (DR) situation?
Access control is also important. An organization tightens security by limiting access to cloud backups. Furthermore, write-once, read-only access protects backup data from being overwritten, altered or deleted.
Cloud backup vs. cloud disaster recovery
Cloud backup and cloud disaster recovery are not the same, but they are connected.
Cloud disaster recovery enables an organization to fail over workloads in the cloud and keep a business running during an unplanned incident. The organization can fail over data, applications and virtual machine (VM) images. At a certain point, however, the organization should fail back to its primary site.
An organization must consider if the disaster recovery provider has enough bandwidth and resources to handle the data transfer, and thus how long it will take to recover. Testing is important and often easier than with traditional disaster recovery, as many providers offer automated tests. A cloud backup provider may also offer disaster recovery in the cloud. Cloud disaster recovery is valuable for smaller businesses that don’t have the funding or resources to support their own DR site. The cloud data center should be far enough away from the organization using it to ensure recovery from any disaster.