System state backup requirements
You can back up and recover a system containing dynamic disks. If a dynamic disk uses the MBR partition table, the total size of its dynamic volumes must not exceed 2TB.
Free system disk space
Backups depend on snapshots created using native Microsoft tools. When a backup session completes, snapshots are automatically deleted.
By default, snapshots are created on the system disk. There must be enough space for them. Space requirements vary depending on your system but sometimes a snapshot can reach the size of the system.
If it is not possible to allocate enough space on the system disk, consider changing the snapshot location to another drive.
Shadow Copy Service (server versions only)
On the server versions of Windows, the Shadow Copy option must be enabled for all drives in the system.