Abstract: Virtual databases are provisioned using point-in-time copies of a source database. Transaction logs received from the source database are applied to a point-in-time copy of the source database to create recovery milestones comprising database blocks that can be used to provision virtual databases. The recovery milestones are created in advance of receiving a request to provision a virtual database. Each recovery milestone is validated to determine that a consistent database snapshot can be created using the recovery milestone. If a problem is identified that prevents creation of a consistent database snapshot, the problem is fixed before creating the next recovery milestone. In response to receiving a request to provision a virtual database corresponding to a point in time, a recovery milestone is identified and transaction logs applied to the recovery milestone to create a database snapshot corresponding to the requested point in time.

Abstract: File system backups are performed by copying information describing changes in the file system since a previous point in time. To restore data, a virtual restored file system (VRFS) structure is created corresponding to a snapshot of data copied from the file system that is stored in the backup file system. A client can read the data stored in the backup file system pointed at by the VRFS structure as well as write to the backup file system. Multiple clients can share blocks of data stored on the backup file system via the same VRFS structure or via multiple VRFS structures. If a client writes to a data block pointed at by a VRFS, a copy of the data block is made to which the client makes changes so that the data in the original data blocks is saved for other clients.