Disc spanning

Disc Spanning (also sometimes referred to as Volume Spanning) is a method of combining multiple physical storage devices (hard drives, solid-state drives) into a single logical volume or drive letter. It is a form of disk virtualization. Unlike RAID configurations such as RAID 1 (mirroring) or RAID 5 (striping with parity), disc spanning does not offer redundancy or performance improvements. Instead, it primarily focuses on increasing the available storage space beyond the capacity of a single drive.

How it Works:

Disc spanning operates by concatenating the physical storage devices. Data is written to the first drive in the span until it is full. Once the first drive reaches capacity, the system begins writing data to the second drive, and so on, until all drives in the span are utilized. This process is sequential and continues across all physical drives configured as part of the spanned volume.

Characteristics and Considerations:

• No Redundancy: If any single drive within the spanned volume fails, the entire volume is lost. Data recovery can be complex and may be impossible.
• No Performance Improvement: Disc spanning does not offer any inherent speed benefits. Write performance is limited by the write speed of the current drive being written to. Once that drive is full, the write performance becomes that of the next drive.
• Easy Implementation: Disc spanning is relatively straightforward to set up using built-in operating system tools or third-party software.
• Flexibility: Spanning allows combining drives of different sizes. The total capacity of the spanned volume is the sum of the capacities of all the member drives.
• File System Limitations: Certain file systems may have limitations on the maximum size of a volume, potentially restricting the number or size of drives that can be spanned.
• Common Use Cases: Disc spanning is primarily used in situations where maximizing available storage space is more important than data protection or performance, and when a single, large logical volume is desired. It is less common in critical environments where data loss is unacceptable.

Alternatives:

Consider RAID configurations (especially RAID 1, RAID 5, RAID 6, RAID 10) for improved data protection and/or performance. Also, investigate storage virtualization solutions for more advanced management and scalability. Simple volume extension within a single physical disk is also an option where possible.