Windows Storage Spaces

A modern way of utilizing multiple physical storage devices to manage storage of large amounts of data on Microsoft-Windows.

Storage Spaces work with any type of storage device, and the group of storage devices that are going to be used don't all have to be the same. Windows will take all of the available space on the storage devices and pool them together, creating a storage pool. The pool is not a physical drive, but a logical concept managed by the OS itself.

Creation of a storage space can be done, not through the Disk Management utility, but through the Control Panel > System and Security > Storage Spaces > Create a storage space.

The pool can be split into individual modules, each looking like a logical disk drive to the end user, and as far as Windows is concerned, it is one. For example, if we have two drives F: and D: that are using the empty storage of a storage pool, even though the actual storage space might span across three or four physical hard drives, it only appears as two drives to the end user.

This feature is useful for when a system is starting to run out of storage in the storage pool, the end user can just up and add another physical storage device without any downtime or extra configuration. The moment the new device is added to the storage pool, extra space is allocated and you're no longer running out of space.

Data Protection & Recovery

The problem with using "simple" storage pools is that if only one of the physical storage devices fail, all the data stored in volumes that usage the space of the storage pool are lost.

Resiliency Option	Description	Min. Drive Count
Two-Way Mirror	Places a copy of the data saved in the storage space on both drives.	2
Three-Way Mirror	Stores a copy of each file stored in the storage space on three of the five hard disk drives. Gives less available free storage, but allows for fault tolerance of two drives simultaneously	5
Parity	Similar to RAID 5. Uses parity information to reconstruct lost data in case of a drive failure, in exchange for slight overhead leading to	3
Dual Parity (only accessible on Windows Server)	The same thing as parity, but it writes the parity information to two disks, allowing for fault tolerance of two drives simultaneously	5

Thin Provisioning (Overbooking)

That thing where you lie to the user, telling it that it can use 100 GB of memory when you definitely don't have that amount of space. You basically pray that it doesn't fact check you on that 100 GB of memory you promised them.

When the storage space runs out of disk space, it will automatically unmount, leaving processes vulnerable to data corruption.