The Elements of Storage in the Hybrid Cloud - dummies

The Elements of Storage in the Hybrid Cloud

By Judith Hurwitz, Marcia Kaufman, Fern Halper, Daniel Kirsch

Companies want to find new cost-effective and flexible digital storage solutions to help meet their evolving storage requirements in a hybrid cloud environment. New mobile and digital technologies are among the many market factors that are responsible for an exponential rate of increase in the amount and type of data that companies need to store.

Some stored data needs to be readily available and some needs to be stored for five to seven years or longer for compliance purposes. New technologies like virtualization have helped companies become more efficient and save money but have also created new and costly storage challenges.

For example, some companies found that the savings they expected from consolidating and increasing the utilization of their servers was eaten up by increased spending on storage for a rapidly growing number of virtual machine images.

Types of large-scale cloud storage models

While new methods and innovation in the approach to storage is expected, the following summarizes how large-scale storage is typically managed:

  • Direct attached storage (DAS): In this model, storage is generally done on the local bus. In other words, your storage may be a hard drive that’s internal to your machine or an external drive like a USB storage device, or it might be on a server or a shared network resource on a dedicated server. DAS is generally not directly accessible to other servers, although multiple machines may share this storage. In a DAS arrangement, you generally cannot share data unless you explicitly give access to a user or a group of users.

  • Storage area network (SAN): This is a high-speed network of interconnected storage devices. These storage devices might be servers or optical disk drives or other storage media. There can be a large number of them, depending on your company’s requirements. The architecture is such that all storage devices are accessible by all devices that are on your company’s local area network (LAN) or wide area network (WAN). SANs can require significant configuration and support to install.

  • Network addressable storage (NAS): A NAS is generally constructed as a specialized kind of computer that is connected to a network and that provides file-based storage to other computers. It’s generally easier to install and not as fast as a SAN. The difference between a NAS and a SAN is that a NAS provides a file system, whereas a SAN doesn’t.

Reduce costs with tiered data storage

Here’s something else to keep in mind about data storage. Traditionally, companies assign the data they need to store into different tiers. Tiered storage is the assignment of data to different kinds of media, generally to reduce storage costs. Here are the three kinds of tiers:

  • Tier 1: Refers to data that has been recently accessed or is mission-critical. In other words, you want to have it readily on hand. It’s generally stored on high-quality media. Think of your bank account data. It’s likely that you want to view the last several months of this data.

  • Tier 2: Refers to data that’s rarely accessed. This might be backed up periodically in a corporate environment. Data stored in databases, for example, is often mirrored (copied) by another sever. In a corporate environment, data might be stored this way for three to six months.

  • Tier 3: Data that’s almost never accessed. This data may need to be stored for a long period of time for compliance reasons. In the brokerage industry, for example, the Securities and Exchange Commission (SEC) requires that all transactions and e-mails be stored for up to seven years. The amount of tier 3 data can be huge for a large company.