Читать книгу The Official (ISC)2 CCSP CBK Reference - Leslie Fife, Aaron Kraus - Страница 30

A variety of storage solutions allow cloud computing to work. Two of these are storage area networks (SANs) and network-attached storage (NAS). These and other advances in storage allow a CSP to offer flexible and scalable storage capabilities.

A SAN provides secure storage among multiple computers within a specific customer's domain. A SAN appears like a single disk to the customer, while the storage is spread across multiple locations. This is one type of shared storage that works across a network.

Another type of networked storage is the NAS. This network storage solution uses TCP/IP and allows file-level access. A NAS appears to the customer as a single file system. This is a solution that works well in a cloud computing environment.

The responsibility for choosing the storage technology lies with the CSP and will change over time as new technologies are introduced. These changes should be transparent to the customer. The CSP is responsible for the security of the shared storage resource.

Shared storage can create security challenges if file fragments remain on a disk after it has been deallocated from one customer and allocated to another. A customer has no way to securely wipe the drives in use, as the customer does not control the physical hardware. However, the use of crypto-shredding can make these fragments unusable if recovered.