Книга: Windows Server 2012 R2 Storage, Security, & Networking Pocket Consultant

Getting started with standards-based storage

Getting started with standards-based storage

With standards-based management, the physical layout of disks (spindles) is abstracted, so a “disk” can be a logical reference to a portion of a storage subsystem (a virtual disk) or an actual physical disk. This means a disk simply becomes a unit of storage and volumes can be created to allocate space within disks for file systems.

Taking this concept a few steps further, you can pool available space on disks so that units of storage (virtual disks) can be allocated from this pool on an as-needed basis. These units of storage, in turn, are apportioned with volumes to allocate space and create usable file systems.

Technically, the pooled storage is referred to as a storage pool and the virtual disks created within the pool are referred to as storages spaces. Given a set of “disks,” you can create a single storage pool by allocating all the disks to the pool or create multiple storage pools by allocating disks separately to each pool.

REAL WORLD Trust me when I say this all sounds more complicated than it is. When you throw storage subsystems into the mix, it’s really a three-layered architecture. In Layer 1, the layout of the physical disks is controlled by the storage subsystem. The storage system likely will use some form of RAID to ensure that data is redundant and recoverable in case of failure. In Layer 2, the virtual disks created by the arrays are made available to servers. The servers simply see the disks as storage that can be allocated. Windows Server can apply software-level RAID or other redundancy approaches to help protect against failure. In Layer 3, the server creates volumes on the virtual disks, and these volumes provide the usable file systems for file and data storage.

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