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Online backup has become essentially the same as cloud backup. In the days before the term cloud was used, online backup simply meant backing up to a service provider's site. Now, that site is almost always some kind of cloud.
Customers can pay a service provider to handle backups, with pricing based on capacity, frequency and size of backups; bandwidth; and number of users. SMBs with lower backup volumes and smaller IT teams are prime use cases for online backup. An enterprise using online backup services might own the off-site server.
Organizations can also use traditional backup software to move data to a public cloud. The process is similar to backing up to disk or tape, except the data goes over the network to the provider's site.
How online backup works
Software as a service (SaaS)-based online backup automatically copies data to another site via a secure connection, and allows for on-demand restoration by users. Often, online computer backup is a SaaS product deployed on an appliance or server at the company's data center.
Online backup systems typically run on a schedule determined by the purchased level of service.
An organization can get started with online backup services in multiple ways. The initial online backup can stream over a network connection. Depending on the method used and the amount of data, the initial off-site backup could take days or weeks.
Cloud backup providers often offer a cloud seeding option for a customer's first backup. Instead of doing the intital backup over the network -- which can be time-consuming for large amounts of data -- the provider sends a disk appliance to the customer, who places their backup data on the appliance. The customer then ships the appliance back to the provider, who copies the data to its own server. Subsequent customer backups only need to move changed blocks of data over the network.
By frequently or continuously backing up data remotely, the risk of data loss is significantly diminished. With a high-speed connection and a web browser interface, remote files and folders appear as they are stored externally.
Advantages and features of online backup services
Online data backup is a cost-effective alternative to on-premises tape and disk backup, which can take more time and labor. Tape and disk backup are also harder to scale, and are more prone to errors that can result in lost data.
Automatic online backup takes a lot of the work out of backing up data for SMBs with limited IT staff and resources. According to Steven Rodin of Storagepipe, online backup services:
- back up data within budget and staff constraints;
- optimize on-site data storage by archiving old data off site;
- meet regulatory requirements and adhere to internal policies;
- enable branch offices to back up easily and reliably with no on-site IT support; and
- allow for quick and reliable data retrieval and restoration, minimizing downtime.
Online backup customers can also switch providers more easily than with other forms of backup, so vendor lock-in is not a major concern.
Beyond software and connectivity, an online backup service provider may allow a customer to manage their backups. Customers are advised to test backup and restore capabilities on a consistent basis.
A service-level agreement will outline what a customer expects of their online backup service provider. Among the areas to cover are security, capacity, protection, retention, availability and disaster recovery (DR).
Disadvantages of online backup and security concerns
Any time an organization backs up a large amount of data over a network -- often in the initial phase -- it's going to involve time and bandwidth.
Online backup services can be less expensive at first, but costs related to time and added capacity can add up. Organizations need to ensure they're backing up data that matters, as unstructured data can drive up capacity, cost and restoration time.
An administrator will assign access roles and authorization privileges to other users, such as the IT staff responsible for backups. Online backup provides more flexibility because an administrator can give anyone access, but there is the risk of users having too much accessibility.
Encryption for data at rest and in transport is important for online backup services. As with any encryption, key management is important. Similar to access control, it is easy to delegate key management, but administrators need to be careful about providing too much access.
Geographic redundancy is an important factor. A service provider should have at least one duplicate data center, far from the primary site, in case of a disaster.
Online vs. offline backup
Unlike an online backup, which copies data that is active, an offline backup -- also called a cold backup -- is performed when the database is disconnected from the network and is not accessible for updating.
A hot backup is performed while the system is online and users work on it. Hot backups do not require downtime, but they may impact performance. In addition, if data is altered while the backup is in progress, the resulting copy may not match the final state of the data.