654 results about "Logical block addressing" patented technology

An electronic data flash card accessible by a host computer, includes a flash memory controller connected to a flash memory device, and an input-output interface circuit activated to establish a communication with the host. In an embodiment, the flash card uses a USB interface circuit for communication with the host. A flash memory controller includes an arbitrator for mapping logical addresses with physical block addresses, and for performing block management operations including: storing reassigned data to available blocks, relocating valid data in obsolete blocks to said available blocks and reassigning logical block addresses to physical block addresses of said available blocks, finding bad blocks of the flash memory device and replacing with reserve blocks, erasing obsolete blocks for recycling after relocating valid data to available blocks, and erase count wear leveling of blocks, etc. Furthermore, each flash memory device includes an internal buffer for accelerating the block management operations.

A hybrid solid-state disk (SSD) has multi-level-cell (MLC) or single-level-cell (SLC) flash memory, or both. SLC flash may be emulated by MLC that uses fewer cell states. A NVM controller converts logical block addresses (LBA) to physical block addresses (PBA). Most data is block-mapped and stored in MLC flash, but some critical or high-frequency data is page-mapped to reduce block-relocation copying. A hybrid mapping table has a first-level and a second level. Only the first level is used for block-mapped data, but both levels are used for page-mapped data. The first level contains a block-page bit that indicates if the data is block-mapped or page-mapped. A PBA field in the first-level table maps block-mapped data, while a virtual field points to the second-level table where the PBA and page number is stored for page-mapped data. Page-mapped data is identified by a frequency counter or sector count. SRAM space is reduced.

A disk drive is disclosed comprising a disk having a plurality of data sectors, wherein a physical block address (PBA) is associated with each data sector. When a write command is received from a host to write user data to the disk, and the write command comprises an unformatted logical block address (LBA), the user data is written to a first data sector, and the first data sector is write verified. A second data sector is defect scanned, and after the second data sector passes the defect scan, the user data is migrated from the first data sector to the second data sector and the LBA is formatted to the second data sector.

A restrictive multi-level-cell (MLC) flash memory prohibits regressive page-writes. When a regressive page-write is requested, an empty block having a low wear-level count is found, and data from the regressive page-write and data from pages stored in the old block are written to the empty block in page order. The old block is erased and recycled. A two-level look-up table is stored in volatile random-access memory (RAM). A logical page address from a host is divided by a modulo divider to generate a quotient and a remainder. The quotient is a logical block address that indexes a first-level look-up table to find a mapping entry with a physical block address that selects a row in a second-level look-up table. The remainder locates a column in the row in the second-level look-up table. If any page-valid bits above the column pointed to by the remainder are set, the write is regressive.

A volume provider unit in a computer system detects a logical block address of a read or write I / O accessing a logical volume of a storage device from a host. According to the logical block address fetched, a storage domain of the logical volume is dynamically expanded. Moreover, the storage domain of the logical volume is reduced or expanded according to an instruction of a logical volume capacity reduction or expansion from a host commander part to a volume server.

A disk drive that includes nonvolatile memory monitors the drive's reliability-related parameters to detect real or potential failure events, and records failure-related data in nonvolatile memory, rather than in reserved areas of the disks. The monitoring may be by running a diagnostic routine or by regular or periodic monitoring of disk drive sensors, like temperature and shock sensors. The failure events to be monitored and recorded may include defective data sectors. When a new defective sector is detected after the disk drive has been put into operation, that defective sector is taken out of service and its logical block address (LBA) is mapped to a memory space in the nonvolatile memory rather to a reserved spare sector on the disk. When a read or write command is received for an LBA range that includes the defective sector's LBA, the defective sector is skipped while the whole LBA range of the command is processed and the user data for the defective sector's LBA is read from or written to the mapped memory space in the nonvolatile memory.