Abstract: Apparatus and method for managing multi-device storage systems. In some embodiments, a distributed data set is stored across a group of storage devices. Data from a selected storage device in the group are reconstructed and stored in a spare location. Host access requests associated with the data are serviced from the spare location along a first data path while the data from the spare location are concurrently transferred along a different, second data path to a replacement storage device maintained in an offline condition using a progressive (iterative) copyback process. The replacement storage device is thereafter transitioned to an online condition responsive to the transfer of the data to the replacement storage device.

Abstract: Apparatus and method for managing multi-device storage systems. In some embodiments, a distributed data set is stored across a group of storage devices. Data from a selected storage device in the group are reconstructed and stored in a spare location. Host access requests associated with the data are serviced from the spare location along a first data path while the data from the spare location are concurrently transferred along a different, second data path to a replacement storage device maintained in an offline condition using a progressive (iterative) copyback process. The replacement storage device is thereafter transitioned to an online condition responsive to the transfer of the data to the replacement storage device.

Abstract: Computer systems may loose data when a failure occurs within a system. To counteract such loss of data a backup system may be employed. Common backup systems make a copy of either of the data on a storage device or the data, which has changed, on a storage device. The process of backing up data may involve storing a relatively large amount of data and so is commonly done infrequently, such as once per day. If a computer's data is backed up only once per day, several hours of data may be lost if a computer system fails. Embodiments of the present invention may be used to prevent this type of data loss by backing up more frequently. In order to back up more frequently less data at a time is backed up. Instead of the data undergoing a wholesale backup infrequently, embodiments of the present invention form a timed log of the storage writes performed by the computer system. The log provides a running picture of activity to the computer storage system.

Abstract: Computer systems may loose data when a failure occurs within a system. To counteract such loss of data a backup system may be employed. Common backup systems make a copy of either of the data on a storage device or the data, which has changed, on a storage device. The process of backing up data may involve storing a relatively large amount of data and so is commonly done infrequently, such as once per day. If a computer's data is backed up only once per day, several hours of data may be lost if a computer system fails. Embodiments of the present invention may be used to prevent this type of data loss by backing up more frequently. In order to back up more frequently less data at a time is backed up. Instead of the data undergoing a wholesale backup infrequently, embodiments of the present invention form a timed log of the storage writes performed by the computer system. The log provides a running picture of activity to the computer storage system.

Abstract: Data on a primary data volume is restored by generating an image of the primary data volume at a specified point-time based on data stored on a backup data volume, where the data stored on the backup data volume includes data written to the primary data volume and stamps to indicate when the data was written to the primary data volume. The primary data volume is restored based on the generated image of the primary data volume. Additionally, while the primary data volume is being restored, read/write requests to the primary data volume are satisfied using the generated image of the primary data volume.