Understanding Spanned Volumes
If you have multiple small hard drives and you want to combine them into a single, massive drive letter (e.g., a massive D: drive for storing large video files), you can create a Spanned Volume in Windows. A spanned volume links together unallocated space from 2 to 32 dynamic disks. Data is written sequentially; it fills the first disk completely before overflowing into the second disk. Note: Spanned volumes offer zero fault tolerance. If one disk in the span fails, all data across the entire volume is lost.
Step 1: Open Disk Management
Right-click the Start button and select Disk Management. You must have Administrator privileges to make disk changes.
Step 2: Ensure the Disks are Dynamic
Spanned volumes cannot be created on basic disks; they require dynamic disks. In Disk Management, look at the physical disks listed on the left side (e.g., Disk 1, Disk 2). If they say “Basic”, right-click the disk name (not the unallocated space) and select Convert to Dynamic Disk…. Select the disks you intend to span and click OK.
Step 3: Launch the New Spanned Volume Wizard
Locate the unallocated space on the first disk you want to include in the volume. Right-click that unallocated space and select New Spanned Volume…. The wizard will appear; click Next to continue.
Step 4: Select the Disks to Span
The next screen will show the available dynamic disks on the left, and the disks currently selected for the volume on the right. Highlight a disk on the left (e.g., Disk 2) and click the Add > button to bring it into the spanned volume.
You can adjust the “Select the amount of space in MB” value at the bottom if you only want to use a portion of a disk, or leave it at maximum to consume the entire disk. Add as many disks as you need, then click Next.
Step 5: Assign a Drive Letter and Format
Choose the drive letter you want to assign to this massive new volume (e.g., S: for Span). Click Next.
On the formatting screen, choose the NTFS file system, leave the allocation unit size at Default, and give the volume a descriptive label (like “MediaArchive”). Ensure the “Perform a quick format” box is checked, and click Next, then Finish.
Windows will now combine the physical drives. When you open File Explorer, you will see a single drive letter representing the combined capacity of all the disks you selected.