Abstract: Relatively small capacity solid-state storage devices (SSD) are combined with larger capacity magnetic disk storage devices for storing storage block write data to ensure data consistency. Write operations are stored in a sequential write buffer in an SSD to guarantee the storage of write data and then copied from the sequential write buffer to the destination address in a magnetic disk storage device. The sequential write buffer store write data in locations corresponding to the order of receipt of write operations. Write data from the sequential write buffer is transferred to the magnetic disk storage device in the same order and a checkpoint index is frequently updated to indicate the completion of some transfers. During system initialization, the most recent value of the checkpoint index is retrieved and used as a starting location for transferring write data from the sequential write buffer to the magnetic disk storage device.

Abstract: Solid-state storage devices (SSD) are combined with larger capacity magnetic disk-based RAID arrays for storing write data to ensure data consistency across multiple RAID disks. Write operations are stored in a sequential write buffer in at least one SSD to guarantee their storage and then copied from the sequential write buffer to the destination address in RAID array. The sequential write buffer stores write data in locations corresponding to the order of receipt of write operations. Write data from the sequential write buffer is transferred to the RAID array in the same order and a checkpoint index is frequently updated to indicate the completion of some transfers. During system initialization, a copy of the sequential write buffer and its associated checkpoint index are retrieved and used as a starting location for transferring write data from the sequential write buffer to the magnetic disk storage devices in the RAID array.

Abstract: Relatively small capacity solid-state storage devices (SSD) are combined with larger capacity magnetic disk storage devices for storing storage block write data to ensure data consistency. Write operations are stored in a sequential write buffer in an SSD to guarantee the storage of write data and then copied from the sequential write buffer to the destination address in a magnetic disk storage device. The sequential write buffer store write data in locations corresponding to the order of receipt of write operations. Write data from the sequential write buffer is transferred to the magnetic disk storage device in the same order and a checkpoint index is frequently updated to indicate the completion of some transfers. During system initialization, the most recent value of the checkpoint index is retrieved and used as a starting location for transferring write data from the sequential write buffer to the magnetic disk storage device.